Question

`sin^-1  1/2-2sin^-1  1/sqrt2`

Answer 1

`sin^-1  1/2-2sin^-1  1/sqrt2 =sin^-1  1/2-sin^-1 2xx1/sqrt2sqrt(1-(1/sqrt2)^2)`

`=sin^-1  1/2-sin^-1sqrt2xx1/sqrt2`

`=sin^-1  1/2-sin^-1  1`

`=sin^-1(sin  pi/6)-sin^-1(sin  pi/2)`

`=pi/6-pi/2`

`=-pi/3`