Find the derivative of: y=4e7xcos(6x)\displaystyle {y}=-{4}{e}^{{-{7}{x}}}{\cos{{\left(-{6}{x}\right)}}}.


dydx=\displaystyle \frac{{\left.{d}{y}\right.}}{{\left.{d}{x}\right.}}=   

Now, find the equation of the tangent line to the curve at x=0\displaystyle {x}={0}. Write your answer in mx+b\displaystyle {m}{x}+{b} format.

y=\displaystyle {y}=