Answer:
≈ 5.48 sec
Step-by-step explanation:
Equate the height f(x) to 50, that is
- 5x² + 200 = 50 ( subtract 200 from both sides )
- 5x² = - 150 ( divide both sides by - 5 )
x² = 30 ( take the square root of both sides )
x = [tex]\sqrt{30}[/tex] ≈ 5.48 ( to 2 dec. places )