DIFFERENTIATION- TRIGNOMETRY

If $x=2at^2\ and\ y=t^{3\ ,}$  then find dy/dx

•  $\frac{3t}{4a}$  

•  $\frac{4a}{3t}$  

•  $\frac{4a}{3t}$  

•  $\frac{4}{3t}$  

Differential of $y=\cos^2x$  

•  $\sin^2x$  

•  $2\cos x\sin x$  

•  $-2\cos x\sin x$  

•  $2\cos^2x$  

Differential of  $y=\ \frac{\cos x}{x^2}$  ,is:

•  $-\frac{\left(x\sin x+2\cos x\right)}{x^3}$  

•  $-\frac{\left(x\cos x+2\sin x\right)}{x^3}$  

•  $-\frac{\left(x\sin x+2\cos x\right)}{x^{ }}$  

•  $\frac{\left(x\sin x+2\cos x\right)}{x^2}$  

If y=sinx, for what value of x tangent is parallel to x-axis

• $180\degree$

• $20\degree$

• $60\degree$

• $90\degree$

If  $y=4x^2$  , then find the point on the curve where the tangent makes an angle of  $45\degree$  with the x axis

•  $\left(\frac{1}{2}\ ,\ \frac{1}{3}\right)$  

•  $\left(\frac{1}{4\ },\frac{1}{6}\right)$  

•  $\left(\frac{1}{6},\frac{1}{\left(4\right)}\right)$  

•  $\left(\frac{1}{3},\frac{1}{\left(2\right)}\right)$  

Differential of $y=\cos^2x$

• $\sin^2x$

• $2\cos x\sin x$

• $-2\cos x\sin x$

• $2\cos^2x$