The height y (in feet)of a ball that you throw is given by $y = - \frac { 1 } { 150 } x ^ { 2 } + x + 6$ where x is the horizontal distance (in feet)from where you release the ball. How far away does the ball strike the ground from where you release it? Round to the nearest foot.
A) 156 feet
B) 75 feet
C) 87 feet
D) 6 feet
E) 81 feet

Question

Quizplus · Accepted Answer

The ball strikes the ground when y = 0. So, we solve the equation $ - \frac { 1 } { 150 } x ^ { 2 } + x + 6 = 0$. Using the quadratic formula, we get $x = 75$ or $x = 156$. Since the ball is thrown from a distance of 0 feet, the distance it travels before striking the ground is 156 feet.

The Height Y (In Feet)of a Ball That You Throw y=−1150x2+x+6y = - \frac { 1 } { 150 } x ^ { 2 } + x + 6y=−1501​x2+x+6

The Height Y (In Feet)of a Ball That You Throw $y = - \frac { 1 } { 150 } x ^ { 2 } + x + 6$