Question

Is arcsin(3/3) equals pi/2 why?

Answer 1

3/3=1
arcsin(1)=x
where x is between -pi/2 and pi/2 (inclusive)
taking sin( ) of both sides gives
1=sin(x)
the only solution to this in [-pi/2,pi/2] is
x=pi/2
since sin(pi/2)=1
so arcsin(1)=pi/2