I want an Quadratic equation for this :

h hight is at 35000 ft.
t time is on 120 sec.

zero is axis of symmetry, so c is 35000.

Thank you.

not quite sure what you mean by

t time is on 120 sec

From what you said, it appears that

h = at^2 + 35000

But, from the two data given, it looks like

h(120) = 35000