有無人識得做呢題Physics Question (Mechanics)？

Parabola: y(t) = pt^2 + qt + r


y(2) = 4p + 2q + r = 0.75 ..... (1)

y(3.3) = 10.89p + 3.3q + r = 1.2 ..... (2)

y(4.5) = 20.25p + 4.5q + r = 0.9 ..... (3)


Eq.(2) - Eq.(1): 6.89p + 1.3q = 0.45 ..... (4)

Eq.(3) - Eq.(2): 9.36p + 1.2q = -0.3 ..... (5)

Both Eqs.(4) & (5): p = -0.23846, q = 1.61

Eq.(1): r = 0.75 + 4*0.23846 - 2*1.61 = -1.516


y(t) = -0.23846t^2 + 1.61t - 1.516 meter

v(t) = y'(t) = -0.47692t + 1.61 m/s

a(t) = y"(t) = -0.47692 m/s^2