If the tangents on the ellipse
Question:

If the tangents on the ellipse $4 x^{2}+y^{2}=8$ at the points $(1,2)$ and $(a, b)$ are perpendicular to each other, then $\mathrm{a}^{2}$ is equal to :

1. $\frac{64}{17}$

2. $\frac{2}{17}$

3. $\frac{128}{17}$

4. $\frac{4}{17}$

Correct Option: , 2

Solution: