f(x)=-16x^2 + 40X + 50. Assume time going up to max at x=1.25 is the same as the time going down, calculate the time it takes for the ball to reach the ground.

Question

Modeling quadratic functions.  Zeroes are -.92 and 3.42.

Answer 1

To find the time it takes for the ball to reach the ground, we set f(x) equal to 0 and solve for x.  The x values are your zeros.  I see that you already found your zeros, and they are correct after checking  Good work.  Since time can never be negative, we accept the positive zero.

 

Therefore, it takes the ball approximately 3.42 seconds to reach the ground.