Question

PLEASE HELP!!! A LOT OF POINTS FOR THIS!!

A football is thrown toward the end zone. The function h(x) = –0.1x2 + 2.2x + 1.4 gives the height, in yards, of the football when it is x yards from the quarterback. If the receiver misses the pass, how many yards does the ball travel before it hits the ground? Round your answer to the nearest tenth of a yard.

Answer 1

x = -11 + 3√15 (about 22.6 yards)

Explanation:

-0.1x^2+ 2.2x^2 +1.4 = 0

[ multiply all through by -10]

x^2-22x^2= 14

(x+11)^2=14+(11)^2

(x+11)^2=14+121

(x+11)^2=135

[square root both sides]

x+11=3√15

then,

x=-11+3√15

Answer 2

-0.1x² + 2.2x + 1.4 = 0

x² - 22x - 14 = 0

x = (22 ± √((-22)² - 4(1)(-14)))/2

= (22 ± √540)/2

= (22 ± 6√15)/2

= 11 + 3√15

= about 22.6 yards