Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
BITSAT 2014
Exam
BITSAT
Year
2014
Subject
Mathematics
Chapter
Limits

BITSAT 2014 · Mathematics · Limits

_ x arrow 0 (cosec x)^ 1 / x is equal to :

lim⁡x→0(cosec⁡x)1/log⁡x\lim _{x \rightarrow 0}(\operatorname{cosec} x)^{1 / \log x} is equal to :

Options

  1. A0
  2. B1
  3. C1e\frac{1}{e}
  4. DNone of these

Correct answer

C. 1e\frac{1}{e}

Step-by-step solution

Let y=lim⁡x→0(cosec⁡x)1/log⁡xy=\lim _{x \rightarrow 0}(\operatorname{cosec} x)^{1 / \log x} Taking log⁡\log on both sides, we get log⁡y=lim⁡x→0log⁡cosec⁡xlog⁡x[∞∞\log y=\lim _{x \rightarrow 0} \frac{\log \operatorname{cosec} x}{\log x}\left[\frac{\infty}{\infty}\right. form ]=lim⁡x→0−cot⁡x1/x]=\lim _{x \rightarrow 0} \frac{-\cot x}{1 / x} \quad (ByL' Hospital rule) =−lim⁡x→0xtan⁡x(∵cot⁡x=1tan⁡x)⇒log⁡y=−1⇒y=e−1=1e=-\lim _{x \rightarrow 0} \frac{x}{\tan x} \quad\left(\because \cot x=\frac{1}{\tan x}\right)\Rightarrow \log y=-1\Rightarrow y=e^{-1}=\frac{1}{e} Hence, required limit =1e=\frac{1}{e}
Practice Limits on Quantrex Academy →

More from Limits

Given a real valued function ' f ' such that f(x)=\ array cc ^2\ x\ x^2-[x]^2 & for x>0 1… BITSAT 2024Let f(x)= x, g(x)= x, h(x)=x^2 then _ x arrow 1 (f(g(h(x)))-f(g(h(1))))/(x-1)= BITSAT 2024If f(x)=\ array l x^2-1,0 < x < 2 2 x+3,2 ≤ x < 3 array . , then the quadratic equation… BITSAT 2023_ x arrow 0 (| x|)/(x) is equal to BITSAT 2023The value of _ x arrow 0 (1- (1- x))/(x^4) is BITSAT 2022The value of _ x arrow 0 (1+x)^ (1)/(x) -e+(1)/(2) e x x^2 is BITSAT 2022Value of _ x arrow 0 a^ x -1 x is BITSAT 2021_ x arrow 0 2 ^ 2 3 x x^ 2 is equal to BITSAT 2021_ x arrow 0 x- x x+ ^ 2 x is equal to BITSAT 2021The value of _ x → (3π)/(4) 4 ^ 2 xcosx - x + x x + x is BITSAT 2019The value of a , so that _ x → 0 (1)/(x2)(e^ ax - e^ x - x) = (3)/(2) ,& is BITSAT 2018_ n → ∞ sin [π n^ 2 + 1 ] is equal to BITSAT 2017If _ n → ∞ (an - 1 + n^ 2 1 + n ) = b , where a is finite number, then BITSAT 2017_ n arrow ∞ a^ n +b^ n a^ n -b^ n , where a > b > 1, is equal to BITSAT 2016_ x arrow ∞ ∫_ 0 ^ 2 x x e^ x^ 2 d x e^ 4 x^ 2 equals BITSAT 2015If _ x arrow x ((1)/(x))=A and _ x arrow 0 x ((1)/(x))=B , then which one of the… BITSAT 2015 Full Limits list Limits JEE Maths PYQsJEE Mathematics PYQs All BITSAT PYQs