The function f(x) = -x2 - 9x + 10 shows the relationship between the vertical distance of a diver from a pool's surface f(x), in feet, and the horizontal distance x, in feet, of a diver from the diving board. what is a zero of f(x), and what does it represent?

F(x) is the vertical distance from the diver to the water
the zero is when the diver hits the water
find the value of x that make f(x)=0

0=-x²-9x+10
undistribute -1
0=-1(x²+9x-10)
what 2 numbers multiply to -10 and add to get 9
-1 and 10
0=-1(x+10)(x-1)
set to zero

x+10=0
x=-10, false, you can't go a negative distance

x-1=0
x=1

the zero is at x=1 and it represents when the diver hits the water