How do you evaluate $cos(sin^-1(1/2))$ ?

Question

10517 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-08-08T01:40:50

$cos(sin^(-1) (1/2))=cos(cos^(-1) sqrt(1-(1/2)^2) )=sqrt(1-(1/2)^2)=sqrt 3/2.$

Use $cos^(-1) x = sin^(-1)(+- sqrt(1-x^2))$ .

Here the angle is in Q1. So, + sign is taken.

How do you evaluate cos(sin^-1(1/2))cos(sin^-1(1/2))?