The question was written with dark-blue pen. And I tried to solve this question. I obtained $x$ as it is below. But I cannot obtain $y$ Please show me how to do this.
By the way, $\gamma (t)$ may not be clearly readable. So, I wrote again.
$$\gamma (t)=( \cos ^2 (t)-1/2, \sin(t)\cos (t), \sin (t))$$
Thanks for helping.
-sorry for not writing with MathJax. -