How do you evaluate $tan^-1(sin(pi/2))$ without a calculator?

Question

17286 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-11-04T06:07:54

$tan^(-1)(sin(pi/2))=pi/4$

As $sin(pi/2)=1$ and $tan(pi/4)=1$

$tan^(-1)(sin(pi/2))=tan^(-1)1=pi/4$

How do you evaluate tan^-1(sin(pi/2))tan^-1(sin(pi/2)) without a calculator?