l. (5) If y(t) solves y" + y = δ (tーpi/2) , y(0) = 0, y,(0) = 1, then at t= pi laplace is (a) -1 (b) 1 (c) -2 (d)2 (e) 0
ANWER=1
My question is when i plugin y=pi before changing into -cos(t) i get the answer as 2 and i don't understand how changing it makes a difference or why i even had to change it?