Ray df or ray fd because both of these letters are consecutive in both of the angles.
I hope this helps you
slope=y2-y1/x2-x1
slope=9-15/5-3
slope= -6/2
slope = -3
Sine wave with amplitude 0.25
Period is 4/3
h(t) = 0.25Sin((2Pi/4/3)t) = 0.25Sin((3Pi/2)t)
