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Choose the correct answer in $\Large \int \normalsize\frac{\large \sin^2x-\cos^2x}{\large \sin^2x\cos^2x}dx$ is equal to

$(a)\;tan x+cot x +C\qquad(b)\;tan x+cosec x+C\qquad(c)\;-tan x +cot x+C\qquad(d)\;tanx+sec x+C$

1 Answer

  • $(i)\;\int \sec^2xdx=\tan x+c.$
  • $(ii)\;\int cosec^2xdx=-\cot x+c.$
Given $I=\int\frac{\sin^2x-\cos^2x}{\sin^2x\cos^2x}dx.$
On separating the terms we get,
Cancelling the common terms we get,
But $\frac{1}{\cos^2x}=\sec^2x$ and $\frac{1}{\sin^2x}=cosec^2xdx.
$\qquad=\int\sec^2xdx-\int cosec ^2xdx.$
On integrating,
$\;\;\;=\tan x+\cot x+c.$
Hence A is the correct answer.


answered Feb 3, 2013 by sreemathi.v