Question

$$\mathop {\lim }\limits_{x \to 0} {\left( {\frac{{1 + 5{x^2}}}{{1 + 3{x^2}}}} \right)^{{{\frac{1}{x^2}}}}}$$   is equal to :

A. $$e$$
B. $${e^{\frac{1}{2}}}$$
C. $${e^{ - 2}}$$
D. none of these  
Answer :   none of these
Solution :
$$\eqalign{ & {\text{Limit}} = \mathop {\lim }\limits_{x \to 0} {\left( {1 + 2.\frac{{{x^2}}}{{1 + 3{x^2}}}} \right)^{{{\frac{1}{x^2}}}}} \cr & = \mathop {\lim }\limits_{x \to 0} {\left( {1 + 2.\frac{1}{{3 + \frac{1}{{{x^2}}}}}} \right)^{\left( {3 + \frac{1}{{{x^2}}}} \right).\frac{{\frac{1}{{{x^2}}}}}{{3 + \frac{1}{{{x^2}}}}}}} \cr & = {\left\{ {\mathop {\lim }\limits_{y \to \infty } {{\left( {1 + \frac{2}{y}} \right)}^y}} \right\}^{\mathop {\lim }\limits_{x \to 0} \,\frac{{\frac{1}{{{x^2}}}}}{{3 + \frac{1}{{{x^2}}}}}}} \cr & = {\left( {{e^2}} \right)^{\mathop {\lim }\limits_{x \to 0} \,\frac{1}{{3{x^2} + 1}}}} \cr & = {e^2} \cr} $$

Releted MCQ Question on
Calculus >> Limits

Releted Question 1

lf $$f\left( x \right) = \sqrt {\frac{{x - \sin \,x}}{{x + {{\cos }^2}x}}} ,$$     then $$\mathop {\lim }\limits_{x\, \to \,\infty } f\left( x \right)$$    is-

A. $$0$$
B. $$\infty $$
C. $$1$$
D. none of these
Releted Question 2

If $$G\left( x \right) = - \sqrt {25 - {x^2}} $$     then $$\mathop {\lim }\limits_{x\, \to \,{\text{I}}} \frac{{G\left( x \right) - G\left( I \right)}}{{x - 1}}$$     has the value-

A. $$\frac{1}{{24}}$$
B. $$\frac{1}{{5}}$$
C. $$ - \sqrt {24} $$
D. none of these
Releted Question 3

$$\mathop {\lim }\limits_{n\, \to \,\infty } \left\{ {\frac{1}{{1 - {n^2}}} + \frac{2}{{1 - {n^2}}} + ..... + \frac{n}{{1 - {n^2}}}} \right\}$$        is equal to-

A. $$0$$
B. $$ - \frac{1}{2}$$
C. $$ \frac{1}{2}$$
D. none of these
Releted Question 4

If $$\eqalign{ & f\left( x \right) = \frac{{\sin \left[ x \right]}}{{\left[ x \right]}},\,\,\left[ x \right] \ne 0 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\, = 0,\,\,\,\,\,\,\,\,\,\,\,\,\,\left[ x \right] = 0 \cr} $$
Where \[\left[ x \right]\] denotes the greatest integer less than or equal to $$x.$$ then $$\mathop {\lim }\limits_{x\, \to \,0} f\left( x \right)$$   equals

A. $$1$$
B. $$0$$
C. $$ - 1$$
D. none of these

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Limits


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