# 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

⎞
⎟
⎟
⎟
⎟
⎠