For what values of $\displaystyle {a}$ and $\displaystyle {b}$ is the line $\displaystyle {4}{x}+{y}={b}$ tangent to the curve $\displaystyle {y}={a}{x}^{{{2}}}$ when $\displaystyle {x}=-{4}$?
$\displaystyle {a}=$ Preview Question 6 Part 1 of 2   $\displaystyle {b}=$ Preview Question 6 Part 2 of 2