CÓ LIÊN QUAN ĐẾN TOÁN (vì đây là toán tiếng anh) :)))
helppppppppppppp, ngu cả anh cả toán ;-;
You and your friends are watching Olympic snow skiing and notice that the skier travels in the shape of a parabola. You're interested in the change in height of the skier, and learn that it can be modelled using the equation h= $t^{2}$ - 4t +4, where t is the time in seconds after the skier leaves the top of the slope
a) what is the height of the skiing slope, in metre?
b) how many seconds does it take for the skier to reach the ground?