Solve the following differential equations using the method of the integrating factor. (a) (x 2 9) dy dx x y = 0 (b) dy dx 2 x y = 2, y(0) = 1 Hint: Even if we are unable to perform the necessary integration, we may be able to express the solutions to differential equations as integrals. The idea is to take advantage of the Fundamental Theorem of Calculus; if we need an anti-derivative of a function f(x), we may always use the expression R x a f(t)dt (and we're free to choose the value of a arbitrarily). (c) dy dx tan(x) y = cos2 (x), y(0) = 1