First, I tried solving for the total time of flight, which I got as 100 = 5cos25*t --> t=22 s
Since we know the height at which the object lands, but not at which it is launched, I tried setting up the equation as:
yf = 40 - y0 = y0 + 5sin25*(22) - 1/2(9.8)(22)^2
However, I got y0 = 1183 m...