diff --git a/src/c/funktionen.c b/src/c/funktionen.c
index 4a4a52a..91311d3 100644
--- a/src/c/funktionen.c
+++ b/src/c/funktionen.c
@@ -1,6 +1,10 @@
 #include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <math.h>
 #include "funktionen.h"
 
+
 void welcome() {
     char x[15];
     printf("Hallo! Wie heisst du?\n");
@@ -89,4 +93,212 @@ int i(int v, int r) {
 
 int p(int f, int a) {
     return f / a;
+}
+
+// Function to calculate the sine of an angle in radians
+float sine(float x) {
+	return sin(x);
+}
+
+// Function to calculate the cosine of an angle in radians
+float cosine(float x) {
+	return cos(x);
+}
+
+// Function to calculate the tangent of an angle in radians
+float tangent(float x) {
+	return tan(x);
+}
+
+// Function to calculate the arc sine of a value and return the result in radians
+float arcSine(float x) {
+	if (x >= -1 && x <= 1) {
+		return asin(x);
+	}
+	else {
+		printf("Error: Invalid input for arc sine!\n");
+		return 0;
+	}
+}
+
+// Function to calculate the arc cosine of a value and return the result in radians
+float arcCosine(float x) {
+	if (x >= -1 && x <= 1) {
+		return acos(x);
+	}
+	else {
+		printf("Error: Invalid input for arc cosine!\n");
+		return 0;
+	}
+}
+
+// Function to calculate the arc tangent of a value and return the result in radians
+float arcTangent(float x) {
+	return atan(x);
+}
+
+// Function to convert degrees to radians
+float degreesToRadians(float x) {
+	return x * (M_PI / 180);
+}
+
+// Function to convert radians to degrees
+float radiansToDegrees(float x) {
+	return x * (180 / M_PI);
+}
+
+// Function to calculate the base 10 logarithm of a number and add 1
+float logarithmPlusOne(float x) {
+	if (x > 0) {
+		return log10(x) + 1;
+	}
+	else {
+		printf("Error: Invalid input for logarithm + 1!\n");
+		return 0;
+	}
+}
+
+// Function to calculate the natural logarithm (base e) of a number and add 1
+float naturalLogarithmPlusOne(float x) {
+	if (x > 0) {
+		return log(x) + 1;
+	}
+	else {
+		printf("Error: Invalid input for natural logarithm + 1!\n");
+		return 0;
+	}
+}
+
+// Function to calculate the square root of a number and add 1
+float squareRootPlusOne(float x) {
+	if (x >= 0) {
+		return sqrt(x) + 1;
+	}
+	else {
+		printf("Error: Invalid input for square root + 1!\n");
+		return 0;
+	}
+}
+
+// Function to calculate the cube root of a number and add 1
+float cubeRootPlusOne(float x) {
+	return cbrt(x) + 1;
+}
+
+// Function to calculate the sine of an angle in degrees
+float sineDegrees(float x) {
+	return sin(degreesToRadians(x));
+}
+
+// Function to calculate the cosine of an angle in degrees
+float cosineDegrees(float x) {
+	return cos(degreesToRadians(x));
+}
+
+// Function to calculate the tangent of an angle in degrees
+float tangentDegrees(float x) {
+	return tan(degreesToRadians(x));
+}
+
+// Function to calculate the square of a number
+float square(float x) {
+return x * x;
+}
+
+float squareRoot(float x) {
+if (x >= 0) {
+return sqrt(x);
+} else {
+printf("Error: Invalid input for square root!\n");
+return 0;
+}
+}
+
+// Function to calculate the cube of a number
+float cube(float x) {
+return x * x * x;
+}
+
+// Function to calculate the cube root of a number
+float cubeRoot(float x) {
+return cbrt(x);
+}
+
+// Function to calculate the absolute value of a number
+float absolute(float x) {
+return fabs(x);
+}
+
+// Function to calculate the logarithm (base 10) of a number
+float logarithm(float x) {
+if (x > 0) {
+return log10(x);
+} else {
+printf("Error: Invalid input for logarithm!\n");
+return 0;
+}
+}
+
+// Function to calculate the natural logarithm (base e) of a number
+float naturalLogarithm(float x) {
+if (x > 0) {
+return log(x);
+} else {
+printf("Error: Invalid input for natural logarithm!\n");
+return 0;
+}
+}
+
+// Function to calculate the exponentiation of a number to the power of another number
+float power(float x, float y) {
+return pow(x, y);
+}
+
+// Function to calculate the factorial of a number
+int factorial(int x) {
+if (x >= 0) {
+int result = 1;
+for (int i = 1; i <= x; i++) {
+result *= i;
+}
+return result;
+} else {
+printf("Error: Invalid input for factorial!\n");
+return 0;
+}
+}
+
+// Function to calculate the floor value of a number
+float floorValue(float x) {
+return floor(x);
+}
+
+// Function to calculate the ceiling value of a number
+float ceilingValue(float x) {
+return ceil(x);
+}
+
+// Function to calculate the absolute difference between two numbers
+float absoluteDifference(float x, float y) {
+    return fabs(x - y);
+}
+
+// Function to calculate the maximum of two numbers
+float maximum(float x, float y) {
+    return fmax(x, y);
+}
+
+// Function to calculate the minimum of two numbers
+float minimum(float x, float y) {
+    return fmin(x, y);
+}
+
+// Function to calculate the average of two numbers
+float average(float x, float y) {
+    return (x + y) / 2;
+}
+
+// Function to calculate the remainder of division between two numbers
+float remainderValue(float x, float y) {
+    return fmod(x, y);
 }
\ No newline at end of file
diff --git a/src/c/funktionen.h b/src/c/funktionen.h
index fafa7f8..7f1c547 100644
--- a/src/c/funktionen.h
+++ b/src/c/funktionen.h
@@ -1,6 +1,7 @@
 #ifndef FUNKTIONEN_H
 #define FUNKTIONEN_H
 
+
 void welcome();
 // Die welcome() Funktion fragt den Namen des Benutzers ab und gibt einen entsprechenden Text aus.
 
@@ -43,4 +44,98 @@ int i(int v, int r);
 int p(int f, int a);
 // berechnet den Druck
 
+// Function to calculate the sine of an angle in radians
+float sine(float x);
+
+// Function to calculate the cosine of an angle in radians
+float cosine(float x);
+
+// Function to calculate the tangent of an angle in radians
+float tangent(float x);
+
+// Function to calculate the arc sine of a value and return the result in radians
+float arcSine(float x);
+
+// Function to calculate the arc cosine of a value and return the result in radians
+float arcCosine(float x);
+
+// Function to calculate the arc tangent of a value and return the result in radians
+float arcTangent(float x);
+
+// Function to convert degrees to radians
+float degreesToRadians(float x);
+
+// Function to convert radians to degrees
+float radiansToDegrees(float x);
+
+// Function to calculate the base 10 logarithm of a number and add 1
+float logarithmPlusOne(float x);
+
+// Function to calculate the natural logarithm (base e) of a number and add 1
+float naturalLogarithmPlusOne(float x);
+
+// Function to calculate the square root of a number and add 1
+float squareRootPlusOne(float x);
+
+// Function to calculate the cube root of a number and add 1
+float cubeRootPlusOne(float x);
+
+// Function to calculate the sine of an angle in degrees
+float sineDegrees(float x);
+
+// Function to calculate the cosine of an angle in degrees
+float cosineDegrees(float x);
+
+// Function to calculate the tangent of an angle in degrees
+float tangentDegrees(float x);
+
+// Function to calculate the square of a number
+float square(float x);
+
+// Function to calculate the square root of a number
+float squareRoot(float x);
+
+
+// Function to calculate the cube of a number
+float cube(float x);
+
+// Function to calculate the cube root of a number
+float cubeRoot(float x);
+
+// Function to calculate the absolute value of a number
+float absolute(float x);
+
+// Function to calculate the logarithm (base 10) of a number
+float logarithm(float x);
+
+// Function to calculate the natural logarithm (base e) of a number
+float naturalLogarithm(float x);
+
+// Function to calculate the exponentiation of a number to the power of another number
+float power(float x, float y);
+
+// Function to calculate the factorial of a number
+int factorial(int x);
+
+// Function to calculate the floor value of a number
+float floorValue(float x);
+
+// Function to calculate the ceiling value of a number
+float ceilingValue(float x);
+
+// Function to calculate the absolute difference between two numbers
+float absoluteDifference(float x, float y);
+
+// Function to calculate the maximum of two numbers
+float maximum(float x, float y);
+
+// Function to calculate the minimum of two numbers
+float minimum(float x, float y);
+
+// Function to calculate the average of two numbers
+float average(float x, float y);
+
+// Function to calculate the remainder of division between two numbers
+float remainderValue(float x, float y);
+
 #endif
\ No newline at end of file
diff --git a/src/test/test_funktionen.c b/src/test/test_funktionen.c
index 97ca0fa..75281f6 100644
--- a/src/test/test_funktionen.c
+++ b/src/test/test_funktionen.c
@@ -11,7 +11,88 @@ void tearDown(void)
 {
 }
 
-void test_1000_plus_1(void)
+void test_square(void) {
+    float result = square(2.5);
+    TEST_ASSERT_EQUAL_FLOAT(6.25, result);
+}
+
+void test_squareRoot(void) {
+    float result = squareRoot(9.0);
+    TEST_ASSERT_EQUAL_FLOAT(3.0, result);
+}
+
+void test_cube(void) {
+    float result = cube(2.0);
+    TEST_ASSERT_EQUAL_FLOAT(8.0, result);
+}
+
+void test_cubeRoot(void) {
+    float result = cubeRoot(27.0);
+    TEST_ASSERT_EQUAL_FLOAT(3.0, result);
+}
+
+void test_absolute(void) {
+    float result = absolute(-5.0);
+    TEST_ASSERT_EQUAL_FLOAT(5.0, result);
+}
+
+void test_logarithm(void) {
+    float result = logarithm(100.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 2.0, result);
+}
+
+void test_naturalLogarithm(void) {
+    float result = naturalLogarithm(100.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 4.60517, result);
+}
+
+void test_power(void) {
+    float result = power(2.0, 3.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 8.0, result);
+}
+
+void test_factorial(void) {
+    int result = factorial(5);
+    TEST_ASSERT_EQUAL_INT(120, result);
+}
+
+
+void test_floorValue(void) {
+    float result = floorValue(5.7);
+    TEST_ASSERT_EQUAL_FLOAT(5.0, result);
+}
+
+void test_ceilingValue(void) {
+    float result = ceilingValue(5.2);
+    TEST_ASSERT_EQUAL_FLOAT(6.0, result);
+}
+
+void test_absoluteDifference(void) {
+    float result = absoluteDifference(8.0, 4.5);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 3.5, result);
+}
+
+void test_maximum(void) {
+    float result = maximum(5.0, 9.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 9.0, result);
+}
+
+void test_minimum(void) {
+    float result = minimum(5.0, 9.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 5.0, result);
+}
+
+void test_average(void) {
+    float result = average(5.0, 9.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 7.0, result);
+}
+
+void test_remainderValue(void) {
+    float result = remainderValue(10.5, 3.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 1.5, result);
+}
+
+void test_500_plus_249_plus_251(void)
 {
     /* arrange */
     int actual;
@@ -182,4 +263,94 @@ void test_pressure_at_force360_area12(void)
     TEST_ASSERT_EQUAL_INT(expected, actual);
 }
 
+void test_sine(void) {
+    float result = sine(0.5);
+    TEST_ASSERT_EQUAL_FLOAT(0.479426, result);
+}
+
+void test_cosine(void) {
+    float result = cosine(1.0);
+    TEST_ASSERT_EQUAL_FLOAT(0.540302, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_tangent(void) {
+    float result = tangent(1.5);
+    TEST_ASSERT_EQUAL_FLOAT(14.101419, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_arcSine(void) {
+    float result = arcSine(0.5);
+    TEST_ASSERT_EQUAL_FLOAT(0.523599, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_arcCosine(void) {
+    float result = arcCosine(0.5);
+    TEST_ASSERT_EQUAL_FLOAT(1.047198, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_arcTangent(void) {
+    float result = arcTangent(1.0);
+    TEST_ASSERT_EQUAL_FLOAT(0.785398, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_degreesToRadians(void) {
+    float result = degreesToRadians(90.0);
+    TEST_ASSERT_EQUAL_FLOAT(1.570796, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_radiansToDegrees(void) {
+    float result = radiansToDegrees(1.570796);
+    TEST_ASSERT_EQUAL_FLOAT(90.0, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_logarithmPlusOne(void) {
+    float result = logarithmPlusOne(10.0);
+    TEST_ASSERT_EQUAL_FLOAT(2.0, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_naturalLogarithmPlusOne(void) {
+    float result = naturalLogarithmPlusOne(10.0);
+    TEST_ASSERT_EQUAL_FLOAT(3.302585, result);
+// Add more test cases for different inputs and expected outputs
+
+}
+
+void test_squareRootPlusOne(void) {
+    float result = squareRootPlusOne(9.0);
+    TEST_ASSERT_EQUAL_FLOAT(4.0, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_cubeRootPlusOne(void) {
+    float result = cubeRootPlusOne(8.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 3.0, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_sineDegrees(void) {
+    float result = sineDegrees(45.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 0.7071068, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_cosineDegrees(void) {
+    float result = cosineDegrees(60.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 0.5, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
+void test_tangentDegrees(void) {
+    float result = tangentDegrees(30.0);
+    TEST_ASSERT_FLOAT_WITHIN(0.000001, 0.5773503, result);
+    // Add more test cases for different inputs and expected outputs
+}
+
 #endif
\ No newline at end of file