Question

Find the derivative of $f\left(x\right)$ from the first principle.
$\sin x÷\cos x$

Answer 1

$f\left(x\right)=\sin x÷\cos x$

$\Rightarrow f\left(x\right)=\frac{\sin x}{\cos x}=\tan x$

$\therefore f^{\prime }\left(x\right)={\sec }^{2}x$