Question

please help me big quiz tomorrow!!
the arch of the gateshead bridge millenium bridge forms a parabola with equation y=-.016(x-52.5)^2+45 where the x is the horizontal distance in metera from the archs left end and y is the distance in meters from the base of the arch. What is the width of the arch?

Answer 1

solve for x using the formula \[x=\frac{ -b \pm \sqrt{b ^{2}-4ac} }{ 2a }\]

Answer 2

dont i have to simplify the equation first? or how would i plug it in?

Answer 3

yes simplify it first

Answer 4

and after i put it in the equation what do i do?

Answer 5

how would we find the width?

Answer 6

y=-.016(x-52.5)^2+45
-.016(x-52.5)^2+45=0 divide by -0.016 to get
(x-52.5)^2 - 2812.5=0
x^2 -105x +2756.25-2812.5=0
x^2 -105x +2756.25-2812.5=0
x^2 -105x -56.25=0

Answer 7

ooh i see...

Answer 8

x=105.53, x=0.533
width = 105.53-0.533=104.997 = or 105 m

Answer 9

oooh i think i get it!!!

Answer 10

ok good
correction: sorry
the other x=-0.533 its negative

Answer 11

yea i figured;) thank you very much!!

Answer 12

ok yw...good luck now :D

Answer 13

thank you!!!