Update 04_Math-Functions.md

Added examples

Docs/03_Advanced/04_Math-Functions.md

@@ -14,12 +14,21 @@ unprecise) math functions.
 Unlike previous versions, the fast-math mode applies to all math instructions. Even to default math operations
 like `x / y`.
 
+```C#
+Context context = Context.Create(builder => builder.Math(MathMode.Fast));
+```
+
 ### Forced 32-bit Math
 
 Your kernels might rely on third-party functions that are not under your control.
 These functions typically depend on the default .Net `Math` class, and thus, work on 64-bit floating-point operations.
 You can force the use of 32-bit floating-point operations in all cases using the `Math(MathMode.Fast32BitOnly)` method
 of `Context.Builder`.
-Caution: all doubles will be considered as floats to circumvent issues with third-party code.
+
+```c#
+Context context = Context.Create(builder => builder.Math(MathMode.Fast32BitOnly));
+```
+
+Caution: All doubles will be considered as floats to circumvent issues with third-party code.
 However, this also affects the address computations of array-view elements.
 Avoid the use of this flag unless you know exactly what you are doing.