Transforming arcsin into arctan: asin2atan

### 5.23.10 Transforming arcsin into arctan: asin2atan

The asin2atan command transforms any asins in an expression to atans, using the identity

arcsin(x) = arctan | ⎛ ⎜ ⎜ ⎜ ⎜ ⎝ |
x
√ |
1−x2
| ⎞ ⎟ ⎟ ⎟ ⎟ ⎠

- asin2atan takes one argument:
  expr, an expression containing inverse trigonometric functions.
- asin2atan(expr) returns expr with any asins replaced by the appropriate atans.

#### Example

Input:

asin2atan(asin(x))

Output:

arctan | ⎛ ⎜ ⎜ ⎜ ⎜ ⎝ |
x
√ |
1−x2
| ⎞ ⎟ ⎟ ⎟ ⎟ ⎠