Added logarithmBase2Function for base 2 logarithmic calculations

src/main/c/main_taschenrechner.c

@@ -39,6 +39,7 @@ double tangentFunction(double angle) {
     return tan(angle * M_PI / 180.0);
 }
 
+//..
 // Logarithmic functions
 double logarithmFunction(double x) {
     // Logarithm with base 10
@@ -50,7 +51,10 @@ double naturalLogarithmFunction(double x) {
     return log(x);
 }
 
-
+double logarithmBase2Function(double x) {
+    // Logarithm with base 2
+    return log2(x);
+}
 
 // scientificmode
 int scientificMode(){

src/main/c/taschenrechner.h

@@ -22,6 +22,8 @@ double logarithmFunction(double x);
 
 double naturalLogarithmFunction(double x);
 
+double logarithmBase2Function(double x);
+
 int mode(int userChoice);
 
 int displayMenu();