### 10.2.7 Transforming arccos into arcsin

The acos2asin command transforms arc cosines in an expression to arc sines by using the identity

arccos(x)= |
π
2
| −arcsin(x).

- acos2asin takes expr, an expression containing inverse trigonometric functions.
- acos2asin(expr) returns expr with all instances of acos replaced according to the above formula.

#### Example

acos2asin(acos(x)+asin(x))

Output (after simplification):

π
2