Find the values of `a` for which `sin^(-1)x=|x-a|` will have at least one solution.

Explanation

`y=sinx`

`y=|x-a|`

1)a>0

`y=a-x`

`pi/2=a-1`

`a=1+pi/2`

2)a<0

`y=x-a`

...