Alain throws a stone off a bridge into a river below.

The stone's height (in meters above the water), xxx seconds after Alain threw it, is modeled by:

h(x)=-5x^2+10x+15h(x)=−5x

2

+10x+15h, left parenthesis, x, right parenthesis, equals, minus, 5, x, squared, plus, 10, x, plus, 15

What is the height of the stone at the time it is thrown?