QUESTION 1
[tex]cos\ \theta = \frac{12}{13}\\\theta = cos^{-1}\frac{12}{13} = 22.62\textdegree = 0.3948\ (\text{radians})[/tex]
QUESTION 2
[tex]\frac{3\pi}{2} < \theta < 2\pi\ \text{then find}\ sin(2\theta)[/tex]
First, the fact that we have [tex]sin(2\theta)[/tex] means we have to adjust our range
[tex]\frac{3\pi}{2} < \theta < 2\pi\ \ \text{becomes}\ \ 3\pi < 2\theta < 4\pi\[/tex]
[tex]sin\ 2\theta = \frac{3\pi}{2}\\2\theta = sin^{-1} \frac{3\pi}{2}\\2\theta = \text{error}[/tex]
There are no solutions to inverse sin of [tex]\frac{3\pi}{2}\\[/tex]
