Question

The function f(x) = -x2 - 5x + 50 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 = 5; the diver jumps in the pool at 5 feet per second.
x = 10; the diver jumps in the pool at 10 feet per second.
x = 10; the diver hits the water 10 feet horizontally from the board
x = 5; the diver hits the water 5 feet away horizontally from the board
@abhisar @dan815 @perl @amiste64 @campbell_st

Answer 1

@amistre64

Answer 2

if you factor the quadratic you get

\[f(x) = -(x-10)(x + 5)\]

the zeros of the equation represent when the height is zero, and it will be how far her is from the board.

you need to know that distance can't be negative,

so find the positive zero

Answer 3

well its 50.

Answer 4

the 50 means the board is 50 ft up....

Answer 5

exactly

Answer 6

so the zeros are when he hits the water f(x) = 0 or height = 0. the x value is how far horizontally he is from the board

Answer 7

another posititve zero is 5

Answer 8

substitute x = 5 into the equation, what do you get

oops factored incorrectly it should be

\[f(x) = -(x + 10)(x - 5)\]

Answer 9

i got 50

Answer 10

you mean into (x+10)(x-5)

Answer 11

or not?

Answer 12

@perl @amistre64 @Compassionate