sinX=1

l totally forgot to account for arcsin.

Sorry Wong.

You stated the general solution and that threw me for a loop.

But x= pi/2 was correct.

$\sin X = 1\\ X = \arcsin 1 = \dfrac{\pi}{2}\\ \text{General solution:}X = \dfrac{\pi}{2} + 2n\pi$

Try memorizing a unit circle. They have much needed utility in higher levels of math.

x=0 radians

l should stop answering questions for tonight. Fatigue really messes with your sense of the UC. But that's no excuse. Thank you for the clarification. :D

Don't worry, HSC....we all make mistakes on here......I totally "blew"  a problem, yesterday  !!!!

Realizing your errors is a part of learning........