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Ashton designs movie sets. For one scene, he has to hang a banner across an archway that takes the shape of a parabola modeled by the quadratic equation y= -x^2+ 6x. The banner is to be hung at an angle defined by the linear equation y-x-4, as shown in the figure

Aston needs to know how ling a banner to order. He can find the length using the distance formula if he knows the points in the archway at which ends of the banner are to be attached.

Using the graphing method, find the points at which the equation of the angle of the banner will intersect the equation of the archway

User Jhojan
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1 Answer

3 votes

Answer: The banner must be 4.24 units long

a. Using the graphing method, find the points at which the equation of the angle of the banner will intersect the equation of the archway.

Sample answer:

Please see attached screenshot

Explanation:

The two equations intersect at (1, 5) and (4, 8), so the banner should be hung at these two points.

b. Using the algebraic method, confirm whether the two points obtained by the graphing method are correct.

Sample answer:

Given these two equations:

y = -x2 + 6x (1)

y – x = 4 (2)

Modify equation (2) to get y = x + 4.

To find the points of intersection, equate the two equations:

-x2 + 6x = x + 4

x2 - 5x + 4 = 0

(x – 4)(x – 1) = 0

x = 4 or x = 1.

Substitute the values of x in equation (2) to get the values of y:

y = x + 4

= (4) + 4

= 8.

y = x + 4

= (1) + 4

= 5

The two points of intersection are (4, 8) and (1, 5). These are the same points obtained by graphing.

c. Using the distance formula find the distance between points A and B. How long a banner does Ashton need to order?

Sample answer:

The distance formula is

x1 = 4

y1 = 8

x2 = 1

y2 = 5

Substituting these values in the formula:

d = 4.24 units.

The distance between the two points of intersection of the archway and the banner is 4.24 units, so the banner must be 4.24 units long.

Ashton designs movie sets. For one scene, he has to hang a banner across an archway-example-1
User Dries De Smet
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5.7k points