If $y=e^{6x}\cos 3x$. What is $\frac{d^2y}{dx^2}$?
Answer & explanation
Correct answer: option 2
$\frac{dy}{dx}=e^{6x}(-3\sin 3x+6\cos 6x)$. Differentiating again w.r.to x we get $\frac{d^2y}{dx^2}=9e^{6x}(3\cos 3x-4\sin 3x)$
If $y=e^{6x}\cos 3x$. What is $\frac{d^2y}{dx^2}$?
Correct answer: option 2
$\frac{dy}{dx}=e^{6x}(-3\sin 3x+6\cos 6x)$. Differentiating again w.r.to x we get $\frac{d^2y}{dx^2}=9e^{6x}(3\cos 3x-4\sin 3x)$