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?

x = 1; the diver jumps in the pool at 1 foot per second
x = 10; the diver jumps in the pool at 10 feet per second
x = 1; the diver hits the water 1 foot away horizontally from the board
x = 10; the diver hits the water 10 feet away horizontally from the board

Question

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? 
 	
	x = 1; the diver jumps in the pool at 1 foot per second
	x = 10; the diver jumps in the pool at 10 feet per second
	x = 1; the diver hits the water 1 foot away horizontally from the board
	x = 10; the diver hits the water 10 feet away horizontally from the board