Кристина Плечко 1. dy/dx*1/(y+1)=sinx/cosx, dy/(y+1)=tgxdx, int dy/(y+1)=int tgxdx, ln(y+1)=-ln(cosx)+lnC, y=C/cosx -1. 2. y=sin4x e^2x C1+cos4x e^2x C2.