9. Given that y = ge cos x + de sin x is a two-parameter family of solutions of y" - 2y' + 2y = 0 on the interval (-oo, co), determine whether a member of the family can be found that satisfies the condi- tions (a) y(0) = 1, y'(0) = 0 (b) y(0) = 1, y(7) = -1 (c) y(0) = 1, y(77/2) = 1 (d) y(0) = 0, y( TT) = 0