How do you evaluate sin^-1(sin((3pi)/10))sin1(sin(3π10))?

1 Answer
Sep 23, 2016

(3pi)/103π10.

Explanation:

Let us recall the Defn. of sin^-1sin1 fun. :

sin^-1x=theta, |x| le1 iff sintheta=x, theta in [-pi/2,pi/2]sin1x=θ,|x|1sinθ=x,θ[π2,π2]

:. sin^-1(sintheta)=theta, AAtheta in [-pi/2,pi/2].

In our case. since, 3pi/10 in [-pi/2,pi/2], sin^-1(sin((3pi)/10)=(3pi)/10.