Answer:
Step-by-step explanation:
If we are given the quadratic model, we know that the height of anything on the ground is 0 meters, so that model becomes
[tex]0=-2t^2+4t+16[/tex] I changed your x's to t's since t is for time.
Now we need to factor that quadratic and solve for time:
[tex]0=-2(t^2-2t-8)[/tex]
Since -2 definitely does not equal 0, then
[tex]t^2-2t-8=0[/tex]
Factor that and find t values of 4 and -2. Again, we know that time will never be negative, so
t = 4 seconds.
