Question

Rosa throws a ball. The equation d = −t^2 + 4t + 5 represents the path taken by Rosa's ball where d is the height of the ball (in feet) after t seconds. How long was the ball in the air?

A. 1 second
B. 4 seconds
C. 5 seconds
D. 9 seconds

Answer 1

If I did the math correctly, it should be B

Answer 2

B

Explanation:

-t²+4t+5=0

t²-4t-5=0

t²-5t+t-5=0

t(t-5)+1(t-5)=0

(t-5)(t+1)=0

t=5,-1

when t=0,d=5

actual time it it is in air=5-1=4 seconds.