Question

Найти производную: y=4sin(x)/cos^2(x) ,

Answer 1

$y'=4(\frac{(sinx)'*cos^{2}x -sinx*(cos^{2}x)'}{cos^{4}x} )=4(\frac{cosx*cos^{2}x -sinx*2cosx*(-sinx)}{cos^{4}x} )$$=4(\frac{cos^{2}x +2sinx*sinx}{cos^{3}x} )=4(\frac{sin^{2}x +1}{cos^{3}x} )$