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$\lim_{x\rightarrow \pi } (1+\cos x)/\tan ^{2}x$
asked in Calculus by Active (1.3k points)  
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L $= \frac{1+cos\ x}{tan^2\ x}\\= \frac{1+cos\ x}{sec^2\ x-1}\\ = \frac{1+cos\ x}{ \frac{1-cos^2\ x}{cos^2\ x}}\\ = \frac{(cos^2\ x)(1+cos\ x)}{(1-cos\ x)(1+cos\ x)}\\= \frac{cos^2\ x}{1-cos\ x}$

$\lim_{x \to \pi} L =\lim_{x \to \pi} \frac{cos^2\ x}{1-cos\ x} = \frac{cos^2\ \pi}{1-cos\ \pi}=\frac{(-1)^2}{1-(-1)} = \frac{1}{2}$

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+3 votes
Best answer
$

\lim_{x\rightarrow \pi } (1+\cos x)/\tan ^{2}x $

applying l hospital

$ \lim_{x\rightarrow \pi } (-\sin x)/2*\tan x*sec^{2}x $

it will be

$\lim_{x\rightarrow \pi } (-1)/2*\sec x$

substituting ans will be 1/2
answered by Boss (9.6k points)  
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