
Yefim S. answered 04/10/20
Math Tutor with Experience
Let consider y1·y2' - y1'·y2 = W(t) as linear equation for y2; then if we divide this equation by y1 we get:
y2 - y1'/y1·y2 = W(t)/y1; Integrated factor μ = e ^(-∫y1'/y1dt = e^(-lny1) = 1/y; Then multiplaying by this factor
you will get solution case 3..