Added notes to exercise 94 c_math.

exercises/094_c_math.zig

@@ -1,19 +1,26 @@
 //
 // Often, C functions are used where no equivalent Zig function exists
-// yet. Since the integration of a C function is very simple, as already
+// yet. Okay, that's getting less and less. ;-)
+//
+// Since the integration of a C function is very simple, as already
 // seen in the last exercise, it naturally offers itself to use the
 // very large variety of C functions for our own programs.
 // As an example:
 //
 // Let's say we have a given angle of 765.2 degrees. If we want to
 // normalize that, it means that we have to subtract X * 360 degrees
-// to get the correct angle. How could we do that? A good method is
-// to use the modulo function. But if we write "765.2 % 360", it won't
-// work, because the standard modulo function works only with integer
-// values. In the C library "math", there is a function called "fmod";
-// the "f" stands for floating and means that we can solve modulo for
-// real numbers. With this function, it should be possible to normalize
-// our angle. Let's go.
+// to get the correct angle.
+// How could we do that? A good method is to use the modulo function.
+// But if we write "765.2 % 360", it only works with float values
+// that are known at compile time.
+// In Zig, we would use %mod(a, b) instead.
+//
+// Let us now assume that we cannot do this in Zig, but only with
+// a C function from the standard library. In the library "math",
+// there is a function called "fmod"; the "f" stands for floating
+// and means that we can solve modulo for real numbers. With this
+// function, it should be possible to normalize our angle.
+// Let's go.
 
 const std = @import("std");