SOLUTION: Could please explain to me how to solve: h=-16t^2+21t+40

Question 153470: Could please explain to me how to solve: h=-16t^2+21t+40
Answer by vleith(2983) (Show Source): You can put this solution on YOUR website!
There are many ways to solve a quadratic polynomials For me, unless the problem requires a specific method OR unless the equation is simple enough to 'factor' in my head, I prefer to use the quadratic equation.

Just plug in -16 for a, 21 for b and 40 for c.
Another way to solve, if you have a graphing calculator, is to plot the graph and then see where the the plot crosses the x axis.
In either case, you get the same answers

Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=3001 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: -1.05566824060029, 2.36816824060029. Here's your graph:

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