Найти производные функций y=-ctg2x2-2lnsinx2

Y=-ctg2x2-2lnsinx2 .
y/=-ctg2x2-2lnsinx2/=u±v'=u'±v';un'=n∙un-1∙u';ctgu'=-1sin2u∙u';lnu'=1u∙u'; Cu'=C∙u'.=
=-ctg2x2/-2lnsinx2/=-2∙ctgx2∙ctgx2/-2∙1sinx2∙sinx2/=
=-2∙ctgx2∙-1sin2x2x2/-2∙1sinx2∙cosx2x2/=
=2∙ctgx2∙1sin2x2∙12-2∙cosx2sinx2∙12=ctgx2∙1sin2x2-ctgx2=ctgx2∙1sin2x2-1=
=1sin2α-1=ctg2α=ctgx2∙ctg2x2=ctg3x2
Ответ: y/=ctg3x2