Question

The implied domain of y = arcsin[cos(-2x)] is:
A - [-pi/2 , 0]
B - [0 , pi/2]
C - [/pi , pi]
D - [-pi/4 , pi/4]
E [-2pi , 2pi]

Answer 1

\[
\sin(y)=\cos(-2x)
\]

Answer 2

\[
\cos(\pi/2-y) = \cos(-2x)\implies \pi/2-y = -2x
\]

Answer 3

I'm just messing around.

Answer 4

Okay because I am really confused haha

Answer 5

Okay so basically we want to know the minimum angles to get \[
\cos(-2x)=1,\;\cos(-2x)=-1
\]

Answer 6

0 is one of them.

Answer 7

Honestly, this question is really weird, isn't it?

Answer 8

Yeah haha

Answer 9

I don't see any real restriction on the domain.

Answer 10

Oh well, don't worry, thanks anyway :)