$C$ se phu thuoc theo $\alpha$ theo ham bac nhat$C=a\alpha+b C<=>y ; \alpha<=>x$
ta co $\begin{cases}10=0.a+b \\ 370=180.a+b \end{cases}\rightarrow \begin{cases}a=2\\ b=10 \end{cases}\rightarrow C=2\alpha+10$
$\lambda=c.2\pi \sqrt{LC}\rightarrow C=50 pF\rightarrow \alpha=20^0$