t = 0 (slider from 0 to 10, step 0.1)
α = 0.7853981633974483 rad (slider from 0 to 1.5707963267948966, step 0.017453292519943295)
v_0 = 20 (slider from 0 to 50, step 0.1)
g = 9.81
x_t: v_0 cos(α) t
y_0 = 0
y_t: y_0 + v_0 sin(α) t - 0.5 g t²
P: (x_t, y_t)
s(x) = y_0 + tan(α) x - g / (2 v_0² cos(α)²) x²