So 1 = (180/π).

So 0

On [0, π/2], f(x)=sinx is increasing function.

So here we are 1

f( 1)& lt； f(π)& lt； f(( 180/π))

Namely sin1< sinπ <; sin 1

(Note: You said π, not π)

Because π/4

So cos 1

So cos 1