SOLUTION: hi can you plzz help me with this question...thanks! The path of a basketball shot can be modeled by the equation h = -0.09dē + 0.9d + 2 where h is the height of the basketball, i

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: hi can you plzz help me with this question...thanks! The path of a basketball shot can be modeled by the equation h = -0.09dē + 0.9d + 2 where h is the height of the basketball, i      Log On


   



Question 204443: hi can you plzz help me with this question...thanks!
The path of a basketball shot can be modeled by the equation h = -0.09dē + 0.9d + 2 where h is the height of the basketball, in metres, and d is the horizontal distance of the ball from the player, in metres.
a) What is the maximum height reached by the ball?
b) What is the horizontal distance of the ball from the player when it reaches its maximum height?
c) How far from the floor is the ball when the player releases it?

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Starting with:
h%28d%29+=+-0.09d%5E2%2B0.9d%2B2
a) The maximum h can be found at the vertex of the parabola at:
d+=+%28-0.9%29%2F2%28-0.09%29
d+=+5 Now substitute this value of d into the given equation and solve for h.
h%285%29+=+0.09%285%29%5E2%2B0.9%285%29%2B2
h%285%29+=+4.25
The maximum height is 4.25 metres.
b) The distance d when the ball has reached a height of 4.25 metres is:
4.25+=+-0.09d%5E2%2B0.9d%2B2 Subtract 4.25 from both sides.
-.09d%5E2%2B0.9d-2.25+=+0 Solve using the quadratic formula:x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a where: a = -0.09, b = 0.9, and c = 2.25 and instead of x in the formula, we want to use d, so...
d+=+%28-0.9%2B-sqrt%280.9%5E2-4%28-0.09%29%282.25%29%29%29%2F2%28-0.09%29
d+=+%28-0.9%2B-sqrt%280.81-%28-0.81%29%29%29%2F%28-0.18%29
d+=+%28-0.9%2B-sqrt%281.62%29%29%2F%28-0.18%29
d+=+5metres.
c) From the original equation, the ball is 2 metres from the floor when the player releases it.
The general form of the equation for the height (h) an object propelled upward with an initial velocity v%5B0%5D from an initial height of h%5B0%5D is:
h%28t%29+=+-16t%5E2%2Bv%5B0%5Dt%2Bh%5B0%5D and h%5B0%5D = 2.