If $y = 3e^{2x}+2e^{3x}$, then $\frac{d^2y}{dx^2}-5\frac{dy}{dx}$ is equal to: |
6y -6y 5y -4y |
-6y |
$y=3e^{2x}+2e^{3x}.$ $\frac{dy}{dx}=6e^{2x}+6e^{3x}.$ $\frac{d^2y}{dx^2}=12e^{2x}+18e^{3x}.$ $\frac{d^2y}{dx^2}-5\frac{dy}{dx}=(12e^{2x}+18e^{3x})-5(6e^{2x}+6e^{3x}).$ $=12e^{2x}+18e^{3x}-30e^{2x}-30e^{3x}.$ $=-18e^{2x}-12e^{3x}.$ $\frac{d^2y}{dx^2}-5\frac{dy}{dx}=-18e^{2x}-12e^{3x}=-6y.$ |