Practicing Success
If $y=\log _e\left(\sin \left(\frac{x^2}{3}-1\right)\right)$ then $\frac{d^2 y}{d x^2}$ is equal to : |
$\frac{2}{3}\left(-\cot \left(\frac{x^2}{3}-1\right)+x ~cosec^2\left(\frac{x^2}{3}-1\right)\right)$ $\frac{2}{3} \cot \left(\frac{x^2}{3}-1\right)-\frac{4 x^2}{9} cosec^2\left(\frac{x^2}{3}-1\right)$ $-\frac{2}{3} \cot \left(\frac{x^2}{3}-1\right)+\frac{4 x^2}{9} cosec^2\left(\frac{x^2}{3}-1\right)$ $\frac{2}{3}\left(\cot \left(\frac{x^2}{3}-1\right)-x ~cosec^2\left(\frac{x^2}{3}-1\right)\right)$ |
$\frac{2}{3} \cot \left(\frac{x^2}{3}-1\right)-\frac{4 x^2}{9} cosec^2\left(\frac{x^2}{3}-1\right)$ |
$y=\log \left[\sin \left(\frac{x^2}{3}-1\right)\right] \Rightarrow \frac{d y}{d x}=\frac{\cos \left(\frac{x^2}{3}-1\right)}{\sin \left(\frac{x^2}{3}-1\right)} \times \frac{2 x}{3}$ so $\frac{d y}{d x}=\frac{2 x}{3} \cot \left(\frac{x^2}{3}-1\right)$ so $\frac{d^2y}{dx^2} = \frac{2}{3} \cot \left(\frac{x^2}{3}-1\right)-\frac{2x}{3} × \frac{2x}{3} cosec^2\left(\frac{x^2}{3}-1\right)$ Option: B |