H= -16t^2 + 541? its been forever since i had to do this and frankly i'm completely lost. if you answer this can you teach me how to do it?

A = -16  b = 0  c = 541
Use the quadratic formula which is
x = [-b +- sq root (b^2 -4*a*c)] / 2*a
x = [-0 +-sq root (0 -4*-16*541)] / 2 * -16
x = + - sq root (0 -4*-16*541) / -32
x = + - sq root (34,624) / -32
x = + - 186.075 / -32

x1 = 186.075 / -32 = -5.81484375
x2 = -186.075 / -32 = 5.81484375