Question 13 (5 points)
determine whether the relationship between the two quantities is proportional. explain

Step-by-step explanation:

When two linear variables are directly proportional, the realtion has the form

Where is the contant ratio of change between variables.

One important characteristic of the direct proportion is that its graph is a straight line which passes through the origin.

However, you can notice in the given image that the line formed by those points won't intercept the origin of the coordinate system.

Therefore, the right answer is the second choice.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this