Please solve theses all the questions. full math

Solve each differential equation by variation of parameters 1. y" + y = cos x y" + y = sec 0 tan 0 3. y" + y = tan x 4. y" - y = sinh 2x er 5. y" - 2y' ty =1+x 6. 2y" + 2y' + y = 4Vx 7. Solve each differential equation by variation of parameters, subject to the initial conditions , y(0)=1,y'(0)=0. y" + 2y' - 8y = 2e-2x - ex 8. y" + 3y' + 2y = sin et 9. Solve each differential equation by variation of parameters, subject to the initial conditions , y(0)=1,y'(0)=0. 2y"+y' - y= x+1