MCQ
$\mathop {\lim }\limits_{x \to 0} \frac{{{4^x} - {9^x}}}{{x({4^x} + {9^x})}} = $
  • $\log \left( {\frac{2}{3}} \right)$
  • B
    $\frac{1}{2}\log \left( {\frac{3}{2}} \right)$
  • C
    $\frac{1}{2}\log \left( {\frac{2}{3}} \right)$
  • D
    $\log \,\left( {\frac{3}{2}} \right)$

Answer

Correct option: A.
$\log \left( {\frac{2}{3}} \right)$
a
(a) $y = \mathop {\lim }\limits_{x \to 0} \frac{{{4^x} - {9^x}}}{{x({4^x} + {9^x})}}$,$\left( {\frac{0}{0}{\rm{form}}} \right)$

Using $L-$ Hospital’s rule,

$y = \mathop {\lim }\limits_{x \to 0} \frac{{{4^x}\log 4 - {9^x}\log 9}}{{({4^x} + {9^x}) + x({4^x}\log 4 + {9^x}\log 9)}}$

==> $y = \frac{{\log 4 - \log 9}}{2}$

==> $y = \frac{{\log {{\left( {\frac{2}{3}} \right)}^2}}}{2} = \log \frac{2}{3}$.

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

A binary number is made up of $16$ bits. The probability of an incorrect bit appearing is $p$ and the errors in different bits are independent of one another. The probability of forming an incorrect number is
In a certain group of 36 people, 18 are wearing hats and 24 are wearing sweaters. If six people are wearing neither a hat nor a sweater, then how many people are wearing both a hat and a sweater?
Equation of the straight line making equal intercepts on the axes and passing through the point $(2, 4)$ is
Choose the correct answer. The value of $\cos^248^\circ-\sin^212^\circ$ is:
[Hint: Use $\cos^2\text{A}-\sin^2\text{B}=\cos(\text{A + B})\cos(\text{A}-\text{B})$]
The number of three digit numbers $\overline{a b c}$ such that the arithmetic mean of $b$ and $c$ and the square of their geometric mean are equal is
If mean deviations about median of $x$ , $2x$ , $3x$ , $4x$ , $5x$ , $6x$ , $7x$ , $8x$ , $9x$ , $10x$  is $30$ , then $|x|$ equals 
If the equation of the parabola, whose vertex is at $(5,4)$ and the directrix is $3 x+y-29=0$, is $x^{2}+a y^{2}+b x y+c x+d y+k=0$ then $a + b + c + d + k$ is equal to
If the quadratic equation ${x^2} + \left( {2 - \tan \theta } \right)x - \left( {1 + \tan \theta } \right) = 0$ has $2$ integral roots, then sum of all possible values of $\theta $ in interval $(0, 2\pi )$ is $k\pi $, then $k$ equals 
How many numbers divisible by $5$ and lying between $3000$ and $4000$ can be formed from the digits $1,\, 2, \,3, \,4,\, 5,\, 6$ (repetition is not allowed)
If $\left\{a_{i}\right\}_{i=1}^{n}$ where $n$ is an even integer, is an arithmetic progression with common difference $1$ , and $\sum \limits_{ i =1}^{ n } a _{ i }=192, \sum \limits_{ i =1}^{ n / 2} a _{2 i }=120$, then $n$ is equal to