Question

If $$x{e^{xy}} - y = {\sin ^2}x$$    then $$\frac{{dy}}{{dx}}$$  at $$x=0$$  is :

A. 0
B. 1  
C. $$-1$$
D. none of these
Answer :   1
Solution :
Differentiating w.r.t. $$x,\,{e^{xy}} + x.{e^{xy}}\left( {y + x\frac{{dy}}{{dx}}} \right) - \frac{{dy}}{{dx}} = 2\sin \,x\cos \,x$$
$$\eqalign{ & {\text{or }}\frac{{dy}}{{dx}}\left\{ {{x^2}.{e^{xy}} - 1} \right\} = \sin \,2x - {e^{xy}} - xy.{e^{xy}} \cr & {\text{When }}x = 0,\,0 - y = 0,\,{\text{i}}{\text{.e}}{\text{., }}y = 0 \cr & \therefore \,\frac{{dy}}{{dx}} = \frac{{0 - 1 - 0}}{{0 - 1}} = 1 \cr} $$

Releted MCQ Question on
Calculus >> Differentiability and Differentiation

Releted Question 1

There exist a function $$f\left( x \right),$$  satisfying $$f\left( 0 \right) = 1,\,f'\left( 0 \right) = - 1,\,f\left( x \right) > 0$$       for all $$x,$$ and-

A. $$f''\left( x \right) > 0$$   for all $$x$$
B. $$ - 1 < f''\left( x \right) < 0$$    for all $$x$$
C. $$ - 2 \leqslant f''\left( x \right) \leqslant - 1$$    for all $$x$$
D. $$f''\left( x \right) < - 2$$   for all $$x$$
Releted Question 2

If $$f\left( a \right) = 2,\,f'\left( a \right) = 1,\,g\left( a \right) = - 1,\,g'\left( a \right) = 2,$$         then the value of $$\mathop {\lim }\limits_{x \to a} \frac{{g\left( x \right)f\left( a \right) - g\left( a \right)f\left( x \right)}}{{x - a}}$$      is-

A. $$-5$$
B. $$\frac{1}{5}$$
C. $$5$$
D. none of these
Releted Question 3

Let $$f:R \to R$$   be a differentiable function and $$f\left( 1 \right) = 4.$$   Then the value of $$\mathop {\lim }\limits_{x \to 1} \int\limits_4^{f\left( x \right)} {\frac{{2t}}{{x - 1}}} dt$$     is-

A. $$8f'\left( 1 \right)$$
B. $$4f'\left( 1 \right)$$
C. $$2f'\left( 1 \right)$$
D. $$f'\left( 1 \right)$$
Releted Question 4

Let [.] denote the greatest integer function and $$f\left( x \right) = \left[ {{{\tan }^2}x} \right],$$    then:

A. $$\mathop {\lim }\limits_{x \to 0} f\left( x \right)$$     does not exist
B. $$f\left( x \right)$$  is continuous at $$x = 0$$
C. $$f\left( x \right)$$  is not differentiable at $$x =0$$
D. $$f'\left( 0 \right) = 1$$

Practice More Releted MCQ Question on
Differentiability and Differentiation


Practice More MCQ Question on Maths Section