Summative Test Review for Algebra 2

Question

In a softball game, the batter's hit can be modeled with the equation y=-9x^2 + 90x +11, where x is the distance of the ball and y is the height of the ball. Find the distance that the ball traveled (i.e. the x-value when the ball hits the ground).

Answer 1

Set y = 0 and solve the resulting quadratic equation for x. Use the quadratic formula (which you should be familiar with).

a = -9

b = 90

c = 11

x = [-b ± √(b² - 4ac)] / (2a)

Plug in the numbers. You will get a positive value and a negative value. The positive value is the correct answer.