(dy)/(dx)=sec^(2)x-(tan x)y+y^(2),quady_(1)=tan x.Companing it with (dy)/(dx)=P(x)+Q(x)y+R(x)y^(2) we get,P(x)=sec^(2)x,Q(x)=-tan x,quad R(x)=1.Since y_(1)=tan x is a panticulan solution let y=tan x+u then (dy)/(dx)=Sec^(2)x+(du)/(dx).multiplying (2) by I ... See the full answer