2. y' tgx = y² – 3y + 2
∫ dy/(y2–3y+2)= ∫ dx/tgx
выделяем полный квадрат,
y2–3y+2=( y–1,5)2–0,25
∫ dy/(( y–1,5)2–0,52)= ∫ cosxdx/sinx
(1/2·(0,5)) · ln |(y–1,5–0,5)/(y–1,5+0,5)||=–ln|sinx|+lnC
ln (y–1,5–0,5)/(y–1,5+0,5)=lnC/sinx
(y–2)/(y–1)=C/sinx