Find the equation of the tangent line to the function $\displaystyle {y}=-{2}{x}^{{4}}-{4}$ at the point $\displaystyle {\left(-{1},-{6}\right)}$. No decimal values!

What is the derivative of y? Preview Question 6 Part 1 of 2  

The equation of the tangent line in $\displaystyle {y}={m}{x}+{b}$ form: Preview Question 6 Part 2 of 2