1. The problem statement, all variables and given/known data Find the general solution to y'' + y = sec3(x) 3. The attempt at a solution Well I can get the characteristic equation: r2 + 1 = 0 r = +-i Then the homogeneous solution is yh = C1excos(x) + C2exsin(x) And I know y = yh + yp but how do I get yp? Ive never dealt with powers of cos, only polynomials and ex, so Im not sure how to construct the particular solution. Thanks for the help!!