From 7cf036b53a00b519355788b6e491f2b8744e78df Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 17:08:32 +0100
Subject: [PATCH 01/14] add files for reihen

---
 src/reihen.c       |  7 +++++++
 src/reihen.h       |  6 ++++++
 test/test_reihen.c | 17 +++++++++++++++++
 3 files changed, 30 insertions(+)
 create mode 100644 src/reihen.c
 create mode 100644 src/reihen.h
 create mode 100644 test/test_reihen.c

diff --git a/src/reihen.c b/src/reihen.c
new file mode 100644
index 0000000..cd80bc3
--- /dev/null
+++ b/src/reihen.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <limits.h>
+#include <stdbool.h>
+
+#include "reihen.h"
+#include "exponent.h"
+#include "logarithmus.h"
\ No newline at end of file
diff --git a/src/reihen.h b/src/reihen.h
new file mode 100644
index 0000000..bb17ea0
--- /dev/null
+++ b/src/reihen.h
@@ -0,0 +1,6 @@
+#ifndef REIHEN_H
+#define REIHEN_H
+
+
+
+#endif // reihen.h
\ No newline at end of file
diff --git a/test/test_reihen.c b/test/test_reihen.c
new file mode 100644
index 0000000..043fc95
--- /dev/null
+++ b/test/test_reihen.c
@@ -0,0 +1,17 @@
+#ifdef TEST
+
+#include "unity.h"
+
+#include "reihen.h"
+#include "exponent.h"
+#include "logarithmus.h"
+
+void setUp(void)
+{
+}
+
+void tearDown(void)
+{
+}
+
+#endif // TEST
\ No newline at end of file

From 12393766b6be409dfc01183bca558d9f1f2456a8 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 17:21:29 +0100
Subject: [PATCH 02/14] refactoring: move exponential function to reihen.c

---
 src/exponent.c          | 22 +---------------------
 src/exponent.h          |  1 -
 src/logarithmus.c       |  1 +
 src/reihen.c            | 22 +++++++++++++++++++++-
 src/reihen.h            |  2 +-
 test/test_exponent.c    | 23 +----------------------
 test/test_logarithmus.c |  1 +
 test/test_reihen.c      | 22 ++++++++++++++++++++++
 8 files changed, 48 insertions(+), 46 deletions(-)

diff --git a/src/exponent.c b/src/exponent.c
index bbe2221..8909d56 100644
--- a/src/exponent.c
+++ b/src/exponent.c
@@ -4,6 +4,7 @@
 
 #include "exponent.h"
 #include "logarithmus.h"
+#include "reihen.h"
 
 double absD(double x){
     if(x<0){
@@ -49,24 +50,3 @@ double powerD(double exp, double base){
     return -1.0;
 }
 
-unsigned long long fac(int x){
-    unsigned long long prod = 1;
-    if(x==0) return 1;
-    for (int i = 1; i <= x; i++){
-        if (prod > ULLONG_MAX / i){
-            break;
-        }
-        prod*=i;
-    }
-    return prod;
-}
-
-
-double exponential(double x){
-    double sum = 0.0;
-    for(int i = 0; i<=21; i++){
-        sum += (1.0/fac(i)*(powerD(i,x)));
-    }
-    return sum;
-}
-
diff --git a/src/exponent.h b/src/exponent.h
index 9b53200..1264177 100644
--- a/src/exponent.h
+++ b/src/exponent.h
@@ -3,7 +3,6 @@
 
 double p(double exp, double base);
 double powerD(double exp, double base);
-double exponential(double x);
 double absD(double x);
 
 #endif // exponent.h
\ No newline at end of file
diff --git a/src/logarithmus.c b/src/logarithmus.c
index 1c613e5..fa6ea62 100644
--- a/src/logarithmus.c
+++ b/src/logarithmus.c
@@ -3,6 +3,7 @@
 
 #include "logarithmus.h"
 #include "exponent.h"
+#include "reihen.h"
 
 double logX(double base, double value){
     if(base == 1.0 || base <= 0.0 || value <= 0.0){
diff --git a/src/reihen.c b/src/reihen.c
index cd80bc3..01fd0a5 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -4,4 +4,24 @@
 
 #include "reihen.h"
 #include "exponent.h"
-#include "logarithmus.h"
\ No newline at end of file
+#include "logarithmus.h"
+
+unsigned long long fac(int x){
+    unsigned long long prod = 1;
+    if(x==0) return 1;
+    for (int i = 1; i <= x; i++){
+        if (prod > ULLONG_MAX / i){
+            break;
+        }
+        prod*=i;
+    }
+    return prod;
+}
+
+double exponential(double x){
+    double sum = 0.0;
+    for(int i = 0; i<=21; i++){
+        sum += (1.0/fac(i)*(powerD(i,x)));
+    }
+    return sum;
+}
\ No newline at end of file
diff --git a/src/reihen.h b/src/reihen.h
index bb17ea0..bd4e520 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -1,6 +1,6 @@
 #ifndef REIHEN_H
 #define REIHEN_H
 
-
+double exponential(double x);
 
 #endif // reihen.h
\ No newline at end of file
diff --git a/test/test_exponent.c b/test/test_exponent.c
index ae49c01..d137507 100644
--- a/test/test_exponent.c
+++ b/test/test_exponent.c
@@ -4,6 +4,7 @@
 
 #include "exponent.h"
 #include "logarithmus.h"
+#include "reihen.h"
 
 void setUp(void)
 {
@@ -101,26 +102,4 @@ void test_exponent_edge_case(void){
     TEST_ASSERT_DOUBLE_WITHIN(0.0001, -1.0, r5);
 }
 
-void test_Exponent_with_positive_number(void){
-    double r1, r2, r3;
-
-    r1 = exponential(0.0);
-    r2 = exponential(1.0);
-    r3 = exponential(2.0);
-
-    TEST_ASSERT_EQUAL_DOUBLE(1.0, r1);
-    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 2.718282, r2);
-    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 7.389056, r3);
-}
-
-void test_Exponent_with_negative_number(void){
-    double r1, r2, r3;
-
-    r1 = exponential(-1.0);
-    r2 = exponential(-2.0);
-
-    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.367879, r1);
-    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.135335, r2);
-}
-
 #endif // TEST
\ No newline at end of file
diff --git a/test/test_logarithmus.c b/test/test_logarithmus.c
index 0f7aba1..7c24c13 100644
--- a/test/test_logarithmus.c
+++ b/test/test_logarithmus.c
@@ -4,6 +4,7 @@
 
 #include "logarithmus.h"
 #include "exponent.h"
+#include "reihen.h"
 
 void setUp(void)
 {
diff --git a/test/test_reihen.c b/test/test_reihen.c
index 043fc95..13d490c 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -14,4 +14,26 @@ void tearDown(void)
 {
 }
 
+void test_Exponent_with_positive_number(void){
+    double r1, r2, r3;
+
+    r1 = exponential(0.0);
+    r2 = exponential(1.0);
+    r3 = exponential(2.0);
+
+    TEST_ASSERT_EQUAL_DOUBLE(1.0, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 2.718282, r2);
+    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 7.389056, r3);
+}
+
+void test_Exponent_with_negative_number(void){
+    double r1, r2, r3;
+
+    r1 = exponential(-1.0);
+    r2 = exponential(-2.0);
+
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.367879, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.135335, r2);
+}
+
 #endif // TEST
\ No newline at end of file

From ea2679568fbaa8ed25d54a9199b5979d97c49960 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 17:33:40 +0100
Subject: [PATCH 03/14] add function to get euler number

---
 src/reihen.c | 4 ++++
 src/reihen.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/src/reihen.c b/src/reihen.c
index 01fd0a5..b9f15e9 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -24,4 +24,8 @@ double exponential(double x){
         sum += (1.0/fac(i)*(powerD(i,x)));
     }
     return sum;
+}
+
+double euler(){
+    return exponential(1);
 }
\ No newline at end of file
diff --git a/src/reihen.h b/src/reihen.h
index bd4e520..20f8a18 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -2,5 +2,6 @@
 #define REIHEN_H
 
 double exponential(double x);
+double euler();
 
 #endif // reihen.h
\ No newline at end of file

From 73e6889e5e8dcb0989b39b8269a50f130c17b1cd Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 19:10:27 +0100
Subject: [PATCH 04/14] add approximation for pi by gauss-legendre

---
 src/reihen.c       | 15 +++++++++++++++
 src/reihen.h       |  1 +
 test/test_reihen.c |  8 ++++++++
 3 files changed, 24 insertions(+)

diff --git a/src/reihen.c b/src/reihen.c
index b9f15e9..4e3ebb0 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -28,4 +28,19 @@ double exponential(double x){
 
 double euler(){
     return exponential(1);
+}
+
+double pi(double eps){
+    double a = 1, b = 1/powerD(0.5, 2), t = 0.25, p = 1;
+    double aNew, piold, pi = 1;
+    do{
+        aNew = .5 * (a + b);
+        b = powerD(0.5 , a * b);
+        t -= p * (a - aNew) * (a - aNew);
+        a = aNew;
+        p *= 2;
+        piold = pi;
+        pi = (a + b) * (a + b) / (4 * t);
+    } while (absD(pi - piold) > eps);
+    return pi;
 }
\ No newline at end of file
diff --git a/src/reihen.h b/src/reihen.h
index 20f8a18..36d8468 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -3,5 +3,6 @@
 
 double exponential(double x);
 double euler();
+double pi();
 
 #endif // reihen.h
\ No newline at end of file
diff --git a/test/test_reihen.c b/test/test_reihen.c
index 13d490c..1329b6f 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -36,4 +36,12 @@ void test_Exponent_with_negative_number(void){
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.135335, r2);
 }
 
+void test_pi(void){
+    double r1;
+
+    r1 = pi(1e-8);
+    
+    TEST_ASSERT_DOUBLE_WITHIN(0.0000001, 3.14159265, r1);
+}
+
 #endif // TEST
\ No newline at end of file

From 26be4d744ab3848b2dd2e9d18e2a67ade185390b Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 19:21:41 +0100
Subject: [PATCH 05/14] add function that converts degrees to radians

---
 src/reihen.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/reihen.c b/src/reihen.c
index 4e3ebb0..b31d063 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -6,6 +6,8 @@
 #include "exponent.h"
 #include "logarithmus.h"
 
+#define PI pi(1e-8)
+
 unsigned long long fac(int x){
     unsigned long long prod = 1;
     if(x==0) return 1;
@@ -30,6 +32,15 @@ double euler(){
     return exponential(1);
 }
 
+double squashDegreesTo360(double x){
+    int multiple = x / 360;
+    return x - (360*multiple);
+}
+
+double radians(double d){
+    return d / PI * 180;
+}
+
 double pi(double eps){
     double a = 1, b = 1/powerD(0.5, 2), t = 0.25, p = 1;
     double aNew, piold, pi = 1;

From 4b9f352ea1bedd83a775a5623215a360d563186d Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 19:42:50 +0100
Subject: [PATCH 06/14] add tests for radians function

---
 src/reihen.c       |  2 +-
 src/reihen.h       |  1 +
 test/test_reihen.c | 19 +++++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/reihen.c b/src/reihen.c
index b31d063..258638c 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -38,7 +38,7 @@ double squashDegreesTo360(double x){
 }
 
 double radians(double d){
-    return d / PI * 180;
+    return d * PI / 180;
 }
 
 double pi(double eps){
diff --git a/src/reihen.h b/src/reihen.h
index 36d8468..19f4b35 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -4,5 +4,6 @@
 double exponential(double x);
 double euler();
 double pi();
+double radians(double d);
 
 #endif // reihen.h
\ No newline at end of file
diff --git a/test/test_reihen.c b/test/test_reihen.c
index 1329b6f..2a30593 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -44,4 +44,23 @@ void test_pi(void){
     TEST_ASSERT_DOUBLE_WITHIN(0.0000001, 3.14159265, r1);
 }
 
+void test_degrees_to_radians(){
+    double r1, r2, r3, r4;
+
+    r1 = radians(90.0);
+    r2 = radians(180.0);
+    r3 = radians(51.6);
+    r4 = radians(36.97);
+
+    printf("%lf\n", r1);
+    printf("%lf\n", r2);
+    printf("%lf\n", r3);
+    printf("%lf\n", r4);
+
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 1.570796, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, pi(1e-8), r2);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.900589, r3);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.645248, r4);
+}
+
 #endif // TEST
\ No newline at end of file

From c5fd68472a11586d7b94f268bd1b9c6f25fe2fa2 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 20:26:59 +0100
Subject: [PATCH 07/14] add sin functions and tests

---
 src/reihen.c       | 20 ++++++++++++++++++++
 src/reihen.h       |  1 +
 test/test_reihen.c | 19 ++++++++++++++-----
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/src/reihen.c b/src/reihen.c
index 258638c..5fe2d8c 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -54,4 +54,24 @@ double pi(double eps){
         pi = (a + b) * (a + b) / (4 * t);
     } while (absD(pi - piold) > eps);
     return pi;
+}
+
+double sinD(double x){
+    if (x>=360.0){
+        x = squashDegreesTo360(x);
+    }
+    double sum = 0.0;
+    double currvalue;
+    x = radians(x);
+    double power;
+    unsigned long long faculty;
+    for (int i = 0; i <= 9; i++)
+    {
+        currvalue = 1.0;
+        currvalue *= powerD(2*i+1,x);
+        currvalue /= (double) fac(2*i+1);
+        if(i%2==0) sum += currvalue;
+        else sum -= currvalue;
+    }
+    return sum;
 }
\ No newline at end of file
diff --git a/src/reihen.h b/src/reihen.h
index 19f4b35..f056dfe 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -5,5 +5,6 @@ double exponential(double x);
 double euler();
 double pi();
 double radians(double d);
+double sinD(double d);
 
 #endif // reihen.h
\ No newline at end of file
diff --git a/test/test_reihen.c b/test/test_reihen.c
index 2a30593..a24ecb7 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -52,15 +52,24 @@ void test_degrees_to_radians(){
     r3 = radians(51.6);
     r4 = radians(36.97);
 
-    printf("%lf\n", r1);
-    printf("%lf\n", r2);
-    printf("%lf\n", r3);
-    printf("%lf\n", r4);
-
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 1.570796, r1);
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, pi(1e-8), r2);
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.900589, r3);
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.645248, r4);
 }
 
+void test_sin(void){
+    double r1, r2, r3, r4;
+
+    r1 = sinD(50.0);
+    r2 = sinD(90.0);
+    r3 = sinD(36.97);
+    r4 = sinD(180.0);
+
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.766044, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 1.0, r2);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.601396, r3);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.0, r4);
+}
+
 #endif // TEST
\ No newline at end of file

From 32b27094cf1565c777dd2b28318fdb16502fa86c Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 20:30:44 +0100
Subject: [PATCH 08/14] refactoring: change parameter and variable names

---
 src/reihen.c | 25 +++++++++++++------------
 src/reihen.h |  6 +++---
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/reihen.c b/src/reihen.c
index 5fe2d8c..649814a 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -20,10 +20,10 @@ unsigned long long fac(int x){
     return prod;
 }
 
-double exponential(double x){
+double exponential(double exp){
     double sum = 0.0;
     for(int i = 0; i<=21; i++){
-        sum += (1.0/fac(i)*(powerD(i,x)));
+        sum += (1.0/fac(i)*(powerD(i,exp)));
     }
     return sum;
 }
@@ -32,13 +32,13 @@ double euler(){
     return exponential(1);
 }
 
-double squashDegreesTo360(double x){
-    int multiple = x / 360;
-    return x - (360*multiple);
+double squashDegreesTo360(double degrees){
+    int multiple = degrees / 360;
+    return degrees - (360*multiple);
 }
 
-double radians(double d){
-    return d * PI / 180;
+double radians(double degrees){
+    return degrees * PI / 180;
 }
 
 double pi(double eps){
@@ -56,19 +56,20 @@ double pi(double eps){
     return pi;
 }
 
-double sinD(double x){
-    if (x>=360.0){
-        x = squashDegreesTo360(x);
+double sinD(double degrees){
+
+    if (degrees>=360.0){
+        degrees = squashDegreesTo360(degrees);
     }
     double sum = 0.0;
     double currvalue;
-    x = radians(x);
+    double radian = radians(degrees);
     double power;
     unsigned long long faculty;
     for (int i = 0; i <= 9; i++)
     {
         currvalue = 1.0;
-        currvalue *= powerD(2*i+1,x);
+        currvalue *= powerD(2*i+1, radian);
         currvalue /= (double) fac(2*i+1);
         if(i%2==0) sum += currvalue;
         else sum -= currvalue;
diff --git a/src/reihen.h b/src/reihen.h
index f056dfe..d9cdf38 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -1,10 +1,10 @@
 #ifndef REIHEN_H
 #define REIHEN_H
 
-double exponential(double x);
+double exponential(double exp);
 double euler();
 double pi();
-double radians(double d);
-double sinD(double d);
+double radians(double degrees);
+double sinD(double degrees);
 
 #endif // reihen.h
\ No newline at end of file

From 7bfc5a1fcef49185f84ae2694dd16e1f1d33cf47 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sat, 3 Feb 2024 20:41:46 +0100
Subject: [PATCH 09/14] refactoring: move helper functions to util.c

---
 src/exponent.c          |  8 +-------
 src/logarithmus.c       |  1 +
 src/reihen.c            | 17 +----------------
 src/util.c              | 28 ++++++++++++++++++++++++++++
 src/util.h              |  8 ++++++++
 test/test_exponent.c    |  1 +
 test/test_logarithmus.c |  1 +
 test/test_reihen.c      |  1 +
 8 files changed, 42 insertions(+), 23 deletions(-)
 create mode 100644 src/util.c
 create mode 100644 src/util.h

diff --git a/src/exponent.c b/src/exponent.c
index 8909d56..2e0d5b3 100644
--- a/src/exponent.c
+++ b/src/exponent.c
@@ -5,13 +5,7 @@
 #include "exponent.h"
 #include "logarithmus.h"
 #include "reihen.h"
-
-double absD(double x){
-    if(x<0){
-        return -1 * x;
-    }
-    return x;
-}
+#include "util.h"
 
 double p(double exp, double base){
     double prod = 1.0;
diff --git a/src/logarithmus.c b/src/logarithmus.c
index fa6ea62..2d440f9 100644
--- a/src/logarithmus.c
+++ b/src/logarithmus.c
@@ -4,6 +4,7 @@
 #include "logarithmus.h"
 #include "exponent.h"
 #include "reihen.h"
+#include "util.h"
 
 double logX(double base, double value){
     if(base == 1.0 || base <= 0.0 || value <= 0.0){
diff --git a/src/reihen.c b/src/reihen.c
index 649814a..e021325 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -5,21 +5,10 @@
 #include "reihen.h"
 #include "exponent.h"
 #include "logarithmus.h"
+#include "util.h"
 
 #define PI pi(1e-8)
 
-unsigned long long fac(int x){
-    unsigned long long prod = 1;
-    if(x==0) return 1;
-    for (int i = 1; i <= x; i++){
-        if (prod > ULLONG_MAX / i){
-            break;
-        }
-        prod*=i;
-    }
-    return prod;
-}
-
 double exponential(double exp){
     double sum = 0.0;
     for(int i = 0; i<=21; i++){
@@ -32,10 +21,6 @@ double euler(){
     return exponential(1);
 }
 
-double squashDegreesTo360(double degrees){
-    int multiple = degrees / 360;
-    return degrees - (360*multiple);
-}
 
 double radians(double degrees){
     return degrees * PI / 180;
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..6930ec9
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <limits.h>
+
+#include "util.h"
+
+double absD(double x){
+    if(x<0){
+        return -1 * x;
+    }
+    return x;
+}
+
+double squashDegreesTo360(double degrees){
+    int multiple = degrees / 360;
+    return degrees - (360*multiple);
+}
+
+unsigned long long fac(int x){
+    unsigned long long prod = 1;
+    if(x==0) return 1;
+    for (int i = 1; i <= x; i++){
+        if (prod > ULLONG_MAX / i){
+            break;
+        }
+        prod*=i;
+    }
+    return prod;
+}
diff --git a/src/util.h b/src/util.h
new file mode 100644
index 0000000..76eb4ba
--- /dev/null
+++ b/src/util.h
@@ -0,0 +1,8 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+double absD(double x);
+double squashDegreesTo360(double degrees);
+unsigned long long fac(int x);
+
+#endif // util.h
\ No newline at end of file
diff --git a/test/test_exponent.c b/test/test_exponent.c
index d137507..bd2fdda 100644
--- a/test/test_exponent.c
+++ b/test/test_exponent.c
@@ -5,6 +5,7 @@
 #include "exponent.h"
 #include "logarithmus.h"
 #include "reihen.h"
+#include "util.h"
 
 void setUp(void)
 {
diff --git a/test/test_logarithmus.c b/test/test_logarithmus.c
index 7c24c13..e8f8da9 100644
--- a/test/test_logarithmus.c
+++ b/test/test_logarithmus.c
@@ -5,6 +5,7 @@
 #include "logarithmus.h"
 #include "exponent.h"
 #include "reihen.h"
+#include "util.h"
 
 void setUp(void)
 {
diff --git a/test/test_reihen.c b/test/test_reihen.c
index a24ecb7..f75c8fa 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -5,6 +5,7 @@
 #include "reihen.h"
 #include "exponent.h"
 #include "logarithmus.h"
+#include "util.h"
 
 void setUp(void)
 {

From ae634ac3a2c467b76409738c9bb3012715302647 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sun, 4 Feb 2024 15:29:21 +0100
Subject: [PATCH 10/14] add cos function

---
 src/exponent.h |  1 -
 src/reihen.c   | 21 ++++++++++++++++++++-
 src/reihen.h   |  1 +
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/exponent.h b/src/exponent.h
index 1264177..e20413c 100644
--- a/src/exponent.h
+++ b/src/exponent.h
@@ -3,6 +3,5 @@
 
 double p(double exp, double base);
 double powerD(double exp, double base);
-double absD(double x);
 
 #endif // exponent.h
\ No newline at end of file
diff --git a/src/reihen.c b/src/reihen.c
index e021325..2190881 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -42,7 +42,6 @@ double pi(double eps){
 }
 
 double sinD(double degrees){
-
     if (degrees>=360.0){
         degrees = squashDegreesTo360(degrees);
     }
@@ -60,4 +59,24 @@ double sinD(double degrees){
         else sum -= currvalue;
     }
     return sum;
+}
+
+double cosD(double degrees){
+    if (degrees>=360.0){
+            degrees = squashDegreesTo360(degrees);
+    }
+    double sum = 0.0;
+    double currvalue;
+    double radian = radians(degrees);
+    double power;
+    unsigned long long faculty;
+    for (int i = 0; i <= 9; i++)
+    {
+        currvalue = 1.0;
+        currvalue *= powerD(2*i, radian);
+        currvalue /= fac(2*i);
+        if(i%2==0) sum += currvalue;
+        else sum -= currvalue;
+    }
+    return sum;
 }
\ No newline at end of file
diff --git a/src/reihen.h b/src/reihen.h
index d9cdf38..cb15a78 100644
--- a/src/reihen.h
+++ b/src/reihen.h
@@ -6,5 +6,6 @@ double euler();
 double pi();
 double radians(double degrees);
 double sinD(double degrees);
+double cosD(double degrees);
 
 #endif // reihen.h
\ No newline at end of file

From 08d0ad16e75a8dd31432ba85346589325fa10b51 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sun, 4 Feb 2024 15:30:10 +0100
Subject: [PATCH 11/14] add tests for cos function

---
 test/test_reihen.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/test/test_reihen.c b/test/test_reihen.c
index f75c8fa..a020dec 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -73,4 +73,23 @@ void test_sin(void){
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.0, r4);
 }
 
+void test_cos(void){
+    double r1, r2, r3, r4;
+
+    r1 = cosD(50.0);
+    r2 = cosD(90.0);
+    r3 = cosD(36.97);
+    r4 = cosD(180.0);
+
+    printf("%lf\n", r1);
+    printf("%lf\n", r2);
+    printf("%lf\n", r3);
+    printf("%lf\n", r4);
+
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.642787, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.0, r2);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.798950, r3);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, -1.0, r4);
+}
+
 #endif // TEST
\ No newline at end of file

From b20392a5acf56766f42b7b874e44891ddb6436e3 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sun, 4 Feb 2024 15:45:23 +0100
Subject: [PATCH 12/14] add tangens function

---
 src/reihen.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/reihen.c b/src/reihen.c
index 2190881..556bece 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -79,4 +79,15 @@ double cosD(double degrees){
         else sum -= currvalue;
     }
     return sum;
+}
+
+double tanD(double degrees){
+    if (degrees>=360.0){
+            degrees = squashDegreesTo360(degrees);
+    }
+    if(degrees == 90.0 || degrees == 270.0){
+        return -1.0;
+    }
+    return sinD(degrees)/cosD(degrees);
+
 }
\ No newline at end of file

From 9feab8998d4028ce66bb2ecc8bc11373285099fc Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Sun, 4 Feb 2024 15:53:35 +0100
Subject: [PATCH 13/14] refactoring: reduce use of variables in sin and cos
 function and delete print functions in tests

---
 src/reihen.c       | 30 ++++++++++--------------------
 test/test_reihen.c |  5 -----
 2 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/src/reihen.c b/src/reihen.c
index 556bece..b58b27e 100644
--- a/src/reihen.c
+++ b/src/reihen.c
@@ -45,19 +45,14 @@ double sinD(double degrees){
     if (degrees>=360.0){
         degrees = squashDegreesTo360(degrees);
     }
+
     double sum = 0.0;
-    double currvalue;
     double radian = radians(degrees);
-    double power;
-    unsigned long long faculty;
-    for (int i = 0; i <= 9; i++)
-    {
-        currvalue = 1.0;
-        currvalue *= powerD(2*i+1, radian);
-        currvalue /= (double) fac(2*i+1);
-        if(i%2==0) sum += currvalue;
-        else sum -= currvalue;
+
+    for (int i = 0; i <= 9; i++){
+        sum += powerD((double) i, -1.0) * (powerD(2.0*i+1, radian) / fac(2.0*i+1));
     }
+    
     return sum;
 }
 
@@ -65,19 +60,14 @@ double cosD(double degrees){
     if (degrees>=360.0){
             degrees = squashDegreesTo360(degrees);
     }
+
     double sum = 0.0;
-    double currvalue;
     double radian = radians(degrees);
-    double power;
-    unsigned long long faculty;
-    for (int i = 0; i <= 9; i++)
-    {
-        currvalue = 1.0;
-        currvalue *= powerD(2*i, radian);
-        currvalue /= fac(2*i);
-        if(i%2==0) sum += currvalue;
-        else sum -= currvalue;
+
+    for (int i = 0; i <= 9; i++){
+        sum += powerD((double) i, -1.0) * (powerD(2*i, radian) / fac(2*i));
     }
+
     return sum;
 }
 
diff --git a/test/test_reihen.c b/test/test_reihen.c
index a020dec..5638120 100644
--- a/test/test_reihen.c
+++ b/test/test_reihen.c
@@ -81,11 +81,6 @@ void test_cos(void){
     r3 = cosD(36.97);
     r4 = cosD(180.0);
 
-    printf("%lf\n", r1);
-    printf("%lf\n", r2);
-    printf("%lf\n", r3);
-    printf("%lf\n", r4);
-
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.642787, r1);
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.0, r2);
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.798950, r3);

From 53203e6e873f0946cd3227b6aebbf46ae0fbc1d1 Mon Sep 17 00:00:00 2001
From: fdai7848 <jan.heidekrueger@informatik.hs-fulda.de>
Date: Wed, 7 Feb 2024 14:46:52 +0100
Subject: [PATCH 14/14] =?UTF-8?q?=C3=A4nderung=20an=20team.md?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 team.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/team.md b/team.md
index 2fa5436..e3d7d03 100644
--- a/team.md
+++ b/team.md
@@ -1,4 +1,4 @@
-- Jan Heidekrüger, fdai7848
+- fdai7848, fdai7848
 - Inna Röhrig, fdai7851
 - Justin Trausch, fdai7720
 - Sophia Weber, fdai7828