Question

Не могу решить ребенку 1 курс найти производную функции сборник лунгу (7.1.57)

Answer 1

$y' = \frac{2sinxcosx(ctgx+1)+sin^2x(- \frac{1}{sin^2x}) }{(ctgx+1)^2} + \frac{-2cosxsinx(tgx+1)+ cos^2x\frac{1}{cos^2x} }{(tgx+1)^2} =\\ = \frac{2cos^2x+sin2x-1}{(ctgx+1)^2} + \frac{1-2sin^2x-sin2x}{(tgx+1)^2} =\\ = \frac{2cos^2x+sin2x-1}{ \frac{(cosx+sinx)^2}{sin^2x} } + \frac{1-2sin^2x-sin2x}{ \frac{(cosx+sinx)^2}{cos^2x} } =\\ = \frac{2cos^2xsin^2x+2sin^3xcosx-sin^2x+cos^2x-2sin^2xcos^2x-2sinxcos^3x}{(cosx+sinx)^2}=\\ = \frac{(sin2x-1)(sin^2x-cos^2x)}{(cosx+sinx)^2} = \frac{cos2x(1-sin2x)}{1+sin2x}$