dy/dx=4(y^4) What I did: dx/dy = 1/(4(y^4); x= the integralof 0.25(y^-4) = -1/12(y^-3) + c The answer is at the back of the book is 3(y^3)(4x+c) + 1 =0..There's a whole dozen of other differential equations I can't do so I must be making some very fundamental mistake. Any help would be very appreciated.