CO 1. Find a general solution of y" - 4y = 21 2. Given the differential equation y" +9y = 7xcos(3x), set up the appropriate form of the general solution (complementary function Ye + particular solution yp), but do not determine the values of the coefficients. 3. Given the differential equation y" - 16y = 3.xetr, set up the appropriate form of the general solution (complementary function yc + particular solution yp, but do not determine the values of the coefficients. (0 7. Find a general solution of the differential equation y(3) – 4y' = 3x - 1. V 5. Find a general solution of the differential equation y" + y + y = cos(x). 6.) Use the method of variation of parameters to find a particular solution of u a 9 7 y" + y = 2 sec(x). 7. Find a particular solution of y(3) + 2y" – 3y = 3 + 4e+ 3e3.7. 8. Let W be the set of all vectors (11, 12, 13, 24) in R' such that 21 22 = X3X1 Is W a subspace of R+ ? (Justify your answer) 9. Given the following system of linear equations, find two solution vectors y and v such that the solution space is the set of all linear combinations of the form (su+tv). X1 - 4x2 -- 3.13 - 774 = 0 2x – 12 + x3 + 7x4 = 0 X'] + 2x2 + 3x3 + 11x4 = 0