Answer
The intersection points are:
$(\frac{1}{\sqrt{2}},\pi/12), (\frac{-1}{\sqrt{2}},5\pi/12), (\frac{1}{\sqrt{2}},3\pi/4)$
Work Step by Step
$sin3\theta=cos3\theta$
$\frac{sin3\theta}{cos3\theta}=1$
$tan3\theta=1$
The periodicity of $tan3\theta$ is $\frac{\pi}{3}$
Therefore, the points of intersection are:
$\theta=\frac{\pi}{12}+n\frac{\pi}{3}$
$\theta$ can take on the values:
$\frac{\pi}{12}, \frac{5\pi}{12},\frac{9\pi}{12}$
The intersection points are:
$(\frac{1}{\sqrt{2}},\pi/12), (\frac{-1}{\sqrt{2}},5\pi/12), (\frac{1}{\sqrt{2}},3\pi/4)$
