Determine the coefficient of x4x^4x4 in the power series of f(x)=excos(x)f(x) = e^x \cos(x)f(x)=excos(x).
−16-\frac{1}{6}−61
−112-\frac{1}{12}−121
16\frac{1}{6}61
112\frac{1}{12}121