Add test for ln function for positive numbers

src/exponent.h

@@ -4,5 +4,6 @@
 double expI(double e, double num);
 double expIN(double e, double num);
 double exponential(double x);
+double logN(double x, double eps);
 
 #endif // exponent.h

test/test_exponent.c

@@ -69,6 +69,22 @@ void test_Exponent_with_negative_number(void){
     TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.135335, r2);
 }
 
+void test_ln_with_positive_number(void){
+    double r1, r2, r3;
+
+    r1 = logN(1.0, 0.000001);
+    r2 = logN(10.0, 0.000001);
+    r3 = logN(2.5, 0.000001);
+
+    printf("Result 1: %lf\n", r1);
+    printf("Result 2: %lf\n", r2);
+    printf("Result 3: %lf\n", r3);
+
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 2.302585, r2);
+    TEST_ASSERT_DOUBLE_WITHIN(0.000001, 0.916290, r3);
+}
+
 
 
 #endif // TEST