Answer:
d = 6+sqrt(42)=12.4807407
Step-by-step explanation:
h= -d² + 12d + 6
The ball is caught at ground level which means h=0
0 = -d² + 12d + 6
Subtract 6 from each side
-6 = -d^2 +12d
Factor out a - sign
-6 =-(d^2-12d)
Divide by -1
6 = d^2 -12 d
Complete the square
-12/2 = -6 then square it = 36
Add 36 to each side
6+36 = d^2 -12d +36
42 = (d-6)^2
Take the square root of each side
±sqrt(42) = sqrt( (d-6)^2)
±sqrt(42) = (d-6)
Add 6 to each side
6±sqrt(42) = (d-6)+6
6±sqrt(42) = d
d = 6+sqrt(42)=12.4807407
d =6- sqrt(42)=-.480740698
Since the distance cannot be negative