# Math Help - Negative in the CAST Diagram

1. ## Negative in the CAST Diagram

Hi again,

If $-sinx=0$, where would it be on the CAST diagram? Would it be in the bottom quadrants (so 180, 270?)

Also, if it's $\frac{2}{3}$ for sin, would it be the top quadrants?

Thanks

2. Originally Posted by watp

If $-sinx=0$, where would it be on the CAST diagram? Would it be in the bottom quadrants (so 180, 270?)

Thanks

In the unit circle $-\sin x = 0$ between quadrants, it has the same solution to $\sin x = 0$ , draw both functions on the same set of axes, you will see!

Originally Posted by watp

Also, if it's $\frac{2}{3}$ for sin, would it be the top quadrants?

Thanks
Correct, for $\sin x = \frac{2}{3}, x\in (0,\pi)$

Yep.