A research probe measures the atmospheric pressure PPP (in kPa) relative to its horizontal distance ddd (in km) from the center of a stable weather system, modeled by the function P(d)=101−120(d2−25)2P(d) = 101 - \frac{1}{20}(d^2 - 25)^2P(d)=101−201(d2−25)2 for d≥0d \ge 0d≥0.
Determine the equation of the normal to the graph of pressure against distance at the point where d=5d = 5d=5.
Select your answer from the options below:
P=101 P = 101 P=101 P=5 P = 5 P=5 d=101 d = 101 d=101 d=5 d = 5 d=5
