Urcite si nevzpomenu, jak se to dela, ale normalne bych postupoval asi takto:
y'' + y' - 6y = 2*x + 3 | y(0) = y'(0) = 0
y'' = 2*x + 3 + 6*y - y'
y''(0) = 2*0 + 3 + 6*y(0) - y'(0) = 3
y' = int(y'') = int(3) = 3*x + c
0 = y'(0) = 3*0 + c = 0 => c=0
y' = 3*x
y = int(y') = int(3*x) = 3/2*x*x + d (nejsem si jisty temi 3/2)
0 = y(0) = 3/2*0*0 + d => d=0
y = 3/2*x*x