MCQ
$\mathop {\lim }\limits_{n \to \infty } \sin [\pi \sqrt {{n^2} + 1} ] = $
  • A
    $\infty $
  • $0$
  • C
    Does not exist
  • D
    None of these

Answer

Correct option: B.
$0$
b
(b) Given limit $ = \mathop {\lim }\limits_{n \to \infty } \,\,\sin \left\{ {n\pi {{\left( {1 + \frac{1}{{{n^2}}}} \right)}^{1/2}}} \right\}$

$ = \mathop {\lim }\limits_{n \to \infty } \,\,\sin \,\left\{ {n\pi \left( {1 + \frac{1}{{2{n^2}}} - \frac{1}{{8{n^4}}} + ...} \right)} \right\}$

$ = \mathop {\lim }\limits_{n \to \infty } \,\,\sin \,\left\{ {n\pi \left( {1 + \frac{1}{{2n}} - \frac{1}{{8{n^3}}} + ...} \right)} \right\}$

$ = \mathop {\lim }\limits_{n \to \infty } \,\,{( - 1)^n}\,\sin \pi \,\left( {\frac{1}{{2n}} - \frac{1}{{8{n^3}}} + ....} \right) = 0.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $\tan (\pi \cos \theta ) = \cot (\pi \sin \theta )$, then $\sin \left( {\theta + \frac{\pi }{4}} \right)$ equals
The matrix $A^2 + 4A - 5I$, where $I$ is identity matrix and $A = \left[ {\begin{array}{*{20}{c}}
1&2\\
4&{ - 3}
\end{array}} \right]$ , equals
The value of $\sqrt {(\log _{0.5}^24)} $ is
The condition that the circle ${(x - 3)^2} + {(y - 4)^2} = {r^2}$ lies entirely within the circle ${x^2} + {y^2} = {R^2},$ is 
Let $f$ be a polynomial function such that $f(3x)\, = f'(x) , f''(x)$, for all $x \in R$. Then
Let $A = \{ 2,\,4,\,6,\,8\} $. $A$ relation $R$ on $A$ is defined by $R = \{ (2,\,4),\,(4,\,2),\,(4,\,6),\,(6,\,4)\} $. Then $R$ is
If $f(x) = \frac{1}{{\sqrt {x + 2\sqrt {2x - 4} } }} + \frac{1}{{\sqrt {x - 2\sqrt {2x - 4} } }}$ for $x > 2$, then $f(11) = $
A ship is fitted with three engines $E_1, E_2$ and $E_3$. The engines function independently of each other with respective probabilities $\frac{1}{2}, \frac{1}{4}$ and $\frac{1}{4}$. For the ship to be operational at least two of its engines must function. Let $X$ denote the event that the ship is operational and let $X _1, X _2$ and $X _3$ denotes respectively the events that the engines $E_1 E_2$ and $E_3$ are functioning. Which of the following is (are) true?

$(A)$ $P\left[X_1^c \mid x\right]=\frac{3}{16}$

$(B)$ $P [$ Exactly two engines of the ship are functioning $\mid X ]=\frac{7}{8}$

$(C)$ $P\left[X \mid X_2\right]=\frac{5}{16}$

$(D)$ $P\left[X \mid X_1\right]=\frac{7}{16}$

${99^{th}}$ term of the series $2 + 7 + 14 + 23 + 34 + .....$ is
The locus of a point whose difference of distance from points $(3, 0)$ and $(-3,0)$ is $4$, is