1) sinx
1) f'(x)=(cosx(cosx-1))'=-sinx(cosx-1)+cosx(-sin)
<span>25a²-9b²=(5a-3b)(5a+3b)</span>
{х=2-у
{8-4у+2y^2+2-у+y^2-8=0
3y^2-5у+2=0
Д=25-4*6=1
у1,2=5+-1/6
у1=1 у2=2/3
{х=1,у=1
{х=4/3,у=2/3