Question
Evaluate the following limit: If $\lim\limits_{\text{x}\rightarrow0}{\text{ kx cosec x}}=\lim\limits_{\text{x}\rightarrow0}\text{ x cosec kx,}{}$ find k.

Answer

$\lim\limits_{\text{x}\rightarrow0}{\text{ kx cosec x}}=\lim\limits_{\text{x}\rightarrow0}\text{ x cosec kx,}{}$ $\lim\limits_{\text{x}\rightarrow0}\text{ kx}\frac{1}{\sin\text{x}}=\lim\limits_{\text{x}\rightarrow0}\text{x}\frac{1}{\sin\text{kx}}$ $\text{k}\lim\limits_{\text{x}\rightarrow0}\Big(\frac{\text{x}}{\sin\text{x}}\Big)=\frac{1}{\text{k}}\lim\limits_{\text{x}\rightarrow0}\Big(\frac{\text{kx}}{\sin\text{kx}}\Big)$ $\text{k}=\frac{1}{\text{k}}$ $\text{k}^2=1$ $\text{k}=\pm1$

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

Find the equations to the straight lines which pass through the point $(h, k)$ and are inclined at angle $\tan^{-1}$ m to the straight line $y = mx + c$.
Prove that: $\cos20^\circ\cos40^\circ\cos80^\circ=\frac{1}{8}$
Find the derivative of the following function from first principle. $\text{x}^3-27$
Prove the following by the principle of mathematical induction: $2 + 5 + 8 + 11 + ... +(3\text{n} - 1) =\frac{1}{2}\text{n}(3\text{n}+1)$ $$
Evaluate the following limit: $\lim\limits_{\text{x}\rightarrow\frac{\pi}{4}}\frac{\text{cosec}^2\text{x}-2}{\cot\text{x}-1}$
For three sets A, B and C, show that. $\text{A}\subset\text{B}\Rightarrow\text{C}-\text{B}\subset\text{C}-\text{A}.$
Prove the following by using the principle of mathematical induction for all n ∈ N:$1.2+2.3+3.4+...+\text{n.(n+1)}=\Big[\frac{\text{n(n+1)(n+2)}}{3}\Big].$
The probability that a student will pass the final examination in both English and Hindi is 0.5 and the probability of passing neither is 0.1. If the probability of passing the English Examination is 0.75. What is the probability of passing the Hindi Examination?
Prove that the area of the parallelogram formed by the lines $a_1x + b_1y + c_1 = 0, a_1x + b_1y+ d_1 = 0, a_2x + b_2y + c_2 = 0, a_2x + b_2y + d_2 = 0$ is $\Big|\frac{(\text{d}_1-\text{c}_1)(\text{d}_2-\text{c}_2)}{\text{a}_1\text{b}_2-\text{a}_2\text{b}_1}\Big|$ sq.units. Deduce the condition for these lines to form a rhombus.
The mean and standard deviation of marks obtained by 50 students of a class in three subjects, mathematics, physics and chemistry are given below:
Subject
Mathematics
Physics
Chemistry
Mean
42
32
40.9
Standard
12
15
20
Deviation
 
 
 
Which of the three subjects shows the highest variability in marks and which shows the lowest?