The time it will take the ball to reach a height of 90feet is 1.2 and 4.4secs
Given the height h (in feet) of the ball t seconds after being kicked expressed as:
h = –16t2 + 90t + 4.
If the ball is at a height of 90feet, hence:
90 = –16t2 + 90t + 4
–16t2 + 90t + 4 - 90 = 0
16t^2 -90t + 86= 0
8t^2 -45t + 43= 0
Factorizing the result to get the values of t:
[tex]t=\frac{45 \pm \sqrt{45^2-4(43)(8)} }{16} \\t=\frac{45 \pm \sqrt{2,025-1376} }{16} \\t=\frac{45 \pm {25.47}}{16} \\t=4.4s \ and\ 1.22secs[/tex]
Hence the time it will take the ball to reach a height of 90feet is 1.2 and 4.4secs
Learn more on quadratic function here: https://brainly.com/question/25841119
