
Quadratic FormulaIf you have quadratic function (parabola) `f(x)=ax^2+bx+c` where `a<0` (as in your case) its maximum value will be `(b^24ac)/(4a)` (that is the height of vertex of parabola), and that maximum...

Quadratic FormulaWe are given the initial speed of the coin and the time it took before it hit the water. The given initial speed is the horizontal speed  that is, the horizontal component of the initial speed....

Quadratic FormulaTake note that the equation is in the form h(t) = at^2 +bt + c. Here, a < 0 so the parabola opens upward. Therefore, the maximum height can be found on the ordinate of the vertex. We will...