Question 239117
I think you meant (please check)
{{{h=-16t^2+30t+6}}}
.
If so, finding the vertex gives you your solution.
Axis of symmetry = -b/2a
Axis of symmetry = -30/2(-16)
Axis of symmetry = -30/-32
Axis of symmetry = 15/16
.
Height, then when t = 15/16:
{{{h=-16(15/16)^2+30(15/16)+6}}}
h = 20.06 feet