MCQ
$\mathop {\lim }\limits_{x \to 0} \,\frac{{{\rm{ln}}\,(\cos x)}}{{{x^2}}}$ is equal to
  • A
    $0$
  • B
    $1$
  • C
    $\frac{1}{2}$
  • $ - \frac{1}{2}$

Answer

Correct option: D.
$ - \frac{1}{2}$
d
(d) Applying  $L-$ Hospital’s rule,

$\mathop {\lim }\limits_{x \to 0} \frac{{\ln (\cos x)}}{{{x^2}}}$$ = \mathop {\lim }\limits_{x \to 0} \frac{{ - \tan x}}{{2x}}$

$ = \mathop {\lim }\limits_{x \to 0} \frac{{ - {{\sec }^2}x}}{2} = \frac{{ - 1}}{2}$.

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 in the expansion of $\Big(\text{x}^{4}-\frac{1}{\text{x}^{3}}\Big)^{15},\text{x}^{-17}$ occurs in rth term, then
All the letters of the word $‘EAMCET’$ are arranged in all possible ways. The number of such arrangements in which two vowels are not adjacent to each other is
If $\mathop {\lim }\limits_{x \to \infty } \left\{ {\ln \left( {{x^2} + 5x} \right) - 2\ln \left( {cx + 1} \right)} \right\} =  - 2$ then
Let $\alpha, \beta, \gamma$ be the three roots of the equation $x ^3+ bx + c =0$. If $\beta \gamma=1=-\alpha$, then $b^3+2 c^3-3 \alpha^3-6 \beta^3-8 \gamma^3$ is equal to $......$.
If the tangents drawn at the point $O (0,0)$ and $P (1+\sqrt{5}, 2)$ on the circle $x ^{2}+ y ^{2}-2 x -4 y =0$ intersect at the point $Q$, then the area of the triangle $OPQ$ is equal to
If the eccentricity of a hyperbola $\frac{{{x^2}}}{9} - \frac{{{y^2}}}{{{b^2}}} = 1,$ which passes through $(K, 2),$ is $\frac{{\sqrt {13} }}{3},$ then the value of $K^2$ is
If the equation ${x^2} + px + q = 0$ and ${x^2} + qx + p = 0$, have a common root, then $p + q + 1 = $
$6$ points in a plane be joined in all possible ways by indefinite straight lines, and if no two of them be coincident or parallel, and no three pass through the same point (with the exception of the original $6$ points). The number of distinct points of intersection is equal to
Let  $\tan (2\pi \left| {\sin \,\theta } \right|) = \cot (2\pi \left| {\cos \,\theta } \right|),$ where  $\theta  \in R$ and  $f(x) = (\left| {\sin \,\theta } \right| + \left| {\cos \,\theta } \right|).$ The value of  $\mathop {\lim }\limits_{x \to \infty } \left[ {\frac{2}{{f(x)}}} \right]$ equals (Here $[\,]$ represents greatest integer function)
If ${a_1},{a_2},....{a_n}$ are positive real numbers whose product is a fixed number $c$, then the minimum value of ${a_1} + {a_2} + ...$ $ + {a_{n - 1}} + 2{a_n}$ is