frac{1+cos theta-sin theta}{1+cos theta+sin t | vedclass

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Question

(A) Let the given expression be $E = \frac{1+\cos 	heta-\sin 	heta}{1+\cos 	heta+\sin 	heta}+\frac{1+\cos 	heta+\sin 	heta}{1+\cos 	heta-\sin \

Vedclass · Accepted Answer

$2 \sec 	heta$

Vedclass · Answer

(A) Let the given expression be $E = \frac{1+\cos 	heta-\sin 	heta}{1+\cos 	heta+\sin 	heta}+\frac{1+\cos 	heta+\sin 	heta}{1+\cos 	heta-\sin 	heta}$.
Taking the common denominator,we get:
$E = \frac{(1+\cos 	heta-\sin 	heta)^2 + (1+\cos 	heta+\sin 	heta)^2}{(1+\cos 	heta+\sin 	heta)(1+\cos 	heta-\sin 	heta)}$.
Using the identity $(a-b)^2 + (a+b)^2 = 2(a^2+b^2)$,where $a = 1+\cos 	heta$ and $b = \sin 	heta$:
Numerator $= 2((1+\cos 	heta)^2 + \sin^2 	heta) = 2(1 + 2\cos 	heta + \cos^2 	heta + \sin^2 	heta) = 2(1 + 2\cos 	heta + 1) = 2(2 + 2\cos 	heta) = 4(1+\cos 	heta)$.
Denominator $= (1+\cos 	heta)^2 - \sin^2 	heta = 1 + 2\cos 	heta + \cos^2 	heta - \sin^2 	heta = 1 + 2\cos 	heta + \cos^2 	heta - (1 - \cos^2 	heta) = 2\cos^2 	heta + 2\cos 	heta = 2\cos 	heta(1+\cos 	heta)$.
Thus,$E = \frac{4(1+\cos 	heta)}{2\cos 	heta(1+\cos 	heta)} = \frac{2}{\cos 	heta} = 2 \sec 	heta$.

$\frac{1+\cos \theta-\sin \theta}{1+\cos \theta+\sin \theta}+\frac{1+\cos \theta+\sin \theta}{1+\cos \theta-\sin \theta}=$

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