Question
If the function $f(x)=\left\{\begin{array}{c}\frac{\log _{e}\left(1-x+x^{2}\right)+\log _{e}\left(1+x+x^{2}\right)}{\sec x-\cos x}, x \in\left(\frac{-\pi}{2}, \frac{\pi}{2}\right)-\{0\} \\ k \end{array}\right.$ is continuous at $x =0$, then $k$ is equal to.

Answer

a
$\lim _{x \rightarrow 0} \frac{\left(\ln \left(1+x^{2}+x^{4}\right)\right) \cos x}{1-\cos ^{2} x}$

$\lim _{x \rightarrow 0} \frac{\left(\frac{\ln \left(1+x^{2}+x^{4}\right)}{x^{2}+x^{4}}\right) x^{2}\left(1+x^{2}\right) \cos x}{\left(\frac{\sin ^{2} x}{x^{2}}\right) x^{2}}=1$

$\therefore k =1$

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 $x + y = k$ is a normal to the parabola ${y^2} = 12x$, then $k$ is
The number of points, having both co-ordinates as integers, that lie in the interior of the triangle with vertices $(0,0),(0,41) $ અને $ (41,0)$ is :
If $P(x_1, y_1)$ and $Q(x_2, y_2)$ are points on $2x + 3y + 1 = 0$ such that $|PA - PB|$ is maximum and $|QA - QB|$ is minimum, where $A(2,0)$ and $B(0,2)$, then value of $x_1 - y_1 + x_2 - y_2 $ is -
Let the determinant of a square matrix $A$ of order $m$ be $m-n$, where $m$ and $n$ satisfy $4 m+n=22$ and $17 m +4 n =93$. If $\operatorname{det}(n \operatorname{adj}(\operatorname{adj}( mA )))=$ $3^{ a } 5^{ b } 6^{ c }$. then $a + b + c$ is equal to:
Let the coefficients of third, fourth and fifth terms in the expansion of $\left(x+\frac{a}{x^{2}}\right)^{n}, x \neq 0,$ be in the ratio $12: 8: 3 .$ Then the term independent of $x$ in the expansion, is equal to ...... .
A point $P$ moves inside a square of area $4$ square units such that it is nearer to point of intersection of its diagonal than any vertex. Area of the region traced by $P$ is
If vertex of a parabola is $(2,-1)$ and the equation of its directrix is $4 x-3 y=21$, then the length of its latus rectum is
$\left| {\,\begin{array}{*{20}{c}}0&{p - q}&{p - r}\\{q - p}&0&{q - r}\\{r - p}&{r - q}&0\end{array}\,} \right| = $
Let $P(\alpha,\beta)$ be a variable point which moves in $x-y$ plane such that $\frac{PA}{PB} = 2$ , where $A(1,0)$ and $B(0,-1)$. If $M$ and $m$ denote respectively the maximum and minimum value of $\alpha + \beta$, then value of $[\frac{M}{m}]$ is- (where [.] denotes the greatest integer function)
The number of positive integral solution of the equation $xyz = 3000$ are