Graph `y = 2 cos(π/4 x + (3π)/4) + 1` Solution: Amplitude: `2` Period: `(2π)/(π/4) =8` Phase shift: `(-3π/4)/(π/4) = -3` Vertical shift:`1` This Graph base on `y=cos(x)`; One of it's period starts at `-3` end at `-3+8 =5`; Top: `2+ 1 =3` Bottom: `-2 +1 = -1`