Answer:
Explanation:
height after x seconds = -16x² - 2x + 600
-16x² - 2x + 600 = 450
16x² + 2x - 150 = 0
8x² + x - 75 = 0
Quadratic formula
x = [-1 ± √(1² – 4·8(-75))] / [2·8]
= [-1 ± √2401] / 16
= [-1 ± 49] /16
= 3, -3⅛
-3⅛ is an extraneous solution, so x = 3 seconds.