If $f'(x)$ is zero in the interval $(a, b)$,then in this interval it is

The value of $\Delta \log f(x) + \Delta^{2}(3^{x})$ is

Let $f$ be a differentiable function such that $f(1) = 2$ and $f'(x) = f(x)$ for all $x \in R$. If $h(x) = f(f(x))$,then $h'(1)$ is equal to

Which of the following statements could be true if $f''(x) = x^{1/3}$?

$I$. $f'(x) = \frac{3}{4}x^{4/3} + 9$	$II$. $f(x) = \frac{9}{28}x^{7/3} - 2$
$III$. $f(x) = \frac{9}{28}x^{7/3} + 6$	$IV$. $f'(x) = \frac{3}{4}x^{4/3} - 4$

If $y = \sqrt{\frac{1 + \tan x}{1 - \tan x}}$,then $\frac{dy}{dx} = $

Let $g(x) \neq 0, g^{\prime}(x) \neq 0, f(x) \neq 0, f^{\prime}(x) \neq 0$. If $F(x)=f(x) g(x)$, $G(x)=f^{\prime}(x) g^{\prime}(x)$, $F^{\prime}(x)=G(x) H(x)$, and $F^{\prime}(x)=F(x) K(x)$, then $H(x)+K(x)=$