If $f(x) = x^3\log_e x$, Then $f''(e^2)$ is equal to |
$5e^4 +12e^2$ $17e^2$ $12e^4 + 5e^2$ $17e^4$ |
$17e^2$ |
The correct answer is Option (2) → $17e^2$ $f(x)=x^3\log_e x$ $f'(x)=3x^2\log_e x+x^3\cdot\frac{1}{x}$ $f'(x)=3x^2\log_e x+x^2$ $f''(x)=\frac{d}{dx}\left(3x^2\log_e x+x^2\right)$ $f''(x)=3\left(2x\log_e x+x^2\cdot\frac{1}{x}\right)+2x$ $f''(x)=3(2x\log_e x+x)+2x$ $f''(x)=6x\log_e x+3x+2x$ $f''(x)=6x\log_e x+5x$ At $x=e^2$ $\log_e(e^2)=2$ $f''(e^2)=6e^2\cdot2+5e^2$ $=12e^2+5e^2$ $=17e^2$ The value of $f''(e^2)$ is $17e^2$. |