Solved it
Initial Question:
\(sec(\theta )=2\)
Convert it to cosine
\(cos(\theta)=\frac{1}{2}\)
Which means
\(\theta = \pm \frac{\pi}{3}\)
\(tan(\theta)=\pm\frac{\sqrt{3}}{1}=\pm\sqrt{3}\)
\(\frac{y}{x}=\pm\sqrt{3}\)
Final answer is.
\(y=\pm\sqrt{3}x\)