If $y={{x}^{2}}-3x+4$ find $\tfrac{dy}{dx}$ at x = 5

If $y={{x}^{2}}+\sqrt{x}$ , find $\frac{dy}{dx}$

If $y=3\sin (-4x)$ ,$\tfrac{dy}{dx}$ is

Find the minimum value of $y={{x}^{2}}-2x-3$

If $y=\cos 3x$ , find $\tfrac{dy}{dx}$

If $y=4{{x}^{3}}-2{{x}^{2}}+x$, find $\tfrac{dy}{dx}$

$\begin{align}  & \text{The radius of a circle is increasing at the rate of 0}\text{.02cm}{{\text{s}}^{-1}}.\text{ Find the rate at which the area is } \\ & \text{increasing when the radius of the circle is 7cm} \\ & \text{(A)  0}\text{.88c}{{\text{m}}^{2}}{{s}^{-1}}\text{  (B) }0.75c{{m}^{2}}{{s}^{-1}}\text{ (C) }0.53c{{m}^{2}}{{s}^{-1}}\text{ (D) }0.35c{{m}^{2}}{{s}^{-1}} \\\end{align}$

$\begin{align}  & \text{If }y=x\sin x,\text{ find }\frac{dy}{dx} \\ & \text{(A) }\sin x+x\cos x\text{ (B) }\sin x+\cos x\text{ (C) }\cos x-x\sin x\text{  (D) }\cos x+x\sin x \\\end{align}$

$\begin{align}  & \text{If }y={{(2x+2)}^{3}},\text{ find }\frac{dy}{dx} \\ & (A)\text{ }6{{(2x+2)}^{2}}\text{ }(B)\text{ }3{{(2x+2)}^{2}}\text{ }(C)\text{ }6(2x+2)\text{    }(D)\text{ }3(2x+2) \\\end{align}$

Find $\frac{dy}{dx}$if y = cos x