Question

The integrating factor of the differentionl equation (1 - y²)dx/dy + yx = ay(-1<y<1) is

(a)  1/y² - 1

(b)  1/√y² - 1

(c)  1/1 - y²

(d)  1/√1 - y²

Answer 1

(d)  (1 - y²) dx/dy + yx = ay