1. The problem statement, all variables and given/known data y"+y=sinx initial conditions: y(90 deg) = 3, y(45 deg) = 2 Calculate y at x = -1 2. Relevant equations y=u+v 3. The attempt at a solution I have gotten the following: r^2 + 1 = 0 Therefore, r1=i and r2 = -i u=(c1)cosx + (c2)sinx v=Asinx + Bcosx v'=Acosx - Bsinx v"=-Asinx - Bcosx -Asinx -Bcosx + Asinx + Bcosx - sinx = 0 everything cancels down to: -sinx = 0. Thus, v=0 Then I get, y=(c1)cosx + (c2)sinx + 0 y(45 deg) shows that c2=2 y(90 deg) shows that c1=3 Thus, y=3cosx + 2sinx y(-1) = -.06204 Could someone please let me know where I am making a mistake? Thank you in advance!