Evaluate the following integrals:

We know cos2x + sin2x = 1, 2sinxcosx = sin2x


Denominator can be written as


cos2x + sin2x + 2sinxcosx = (sinx + cosx)2


Now the given equation becomes



Assume cosx + sinx = t


d(cosx + sinx) = dt


= cosx - sinx


dt = cosx sinx






But t = cosx + sinx



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