Ahorizontal pedestrian bridge is supported from a parabolic arch. the bridge goes
above a roadway that is 40 feet wide. at ground level, the main span of the bridge
is 90 feet wide. at the edge of the roadway, 25 feet from where the arch touches the
ground, the arch is 16 feet high. how tall is the arch at its tallest point?

  about 19.94 ft

Step-by-step explanation:

It is convenient to start with a parabola that opens downward and has a width of ±1 and a height of 1. Its equation is ...

  f(x) = 1 - x²

To make it have a horizontal width of ±45 feet, we need to use a horizontal expansion factor. The equation is then ...

  g(x) = f(x/45) = 1 - (x/45)²

To make it have a height of 16 when x=20, we need a vertical expansion factor.

  h(x) = a·g(x) = a(1 -(x/45)²)

Filling in the given values, we can find the value of the vertical expansion factor, a:

  16 = a(1 -(20/45)²) = a(1 -(4/9)²)

  16 = a(65/81)

  16(81/65) = a = 19 61/65 ≈ 19.94 . . . . . . . . divide by the coefficient of "a"

This makes the equation of the arch be ...

  h(x) = 19.94(1 -(x/45)²)

At the tallest point, x = 0, so the arch is ...

  h(0) = 19.94(1 -0) = 19.94 . . . . feet high

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true

the answer is 15.50 for one mile

b) is slope: 0   y- intercept 15.5