Question

$\underset{x\to 0}{lim}\frac{3\sin x-4{\sin }^{3}x}{x}=$

Answer 1

$\underset{x\to 0}{lim}\frac{3\sin x-4{\sin }^{3}x}{x}\left(\frac{0}{0}form\right)$

$=\underset{x\to 0}{lim}3\times \left(\frac{\sin 3x}{3x}\right)$

$=3\times 1$

$=3$