Question

Given the graphed function below, which of the following ordered pairs are

Answer 1

Answer: Option B.

Step-by-step explanation:

A linear function can be written as:

y = a*x + b

where a is the slope and b is the y-intercept.

if the line passes through the points (ax, ay) and (bx, by) then the slope is:

a = (bx - ax)/(by - ay)

In this case, we can see that the line passes through the points:

(1, 3) and (2, 1)

Then the slope is:

a = (1 - 3)/(2 - 1) = -2

y = -2*x + b

In the graph we also can see that the line intersects the y-axis at y = 5, then b = 5.

The line is:

y = f(x) = -2*x + 5.

the inverse function is such that:

g( f(x)) = x

to find the inverse function of a linear equation, we just could isolate x.

y - 5 = -2x

-y/2 + 2.5 = x

Then we could write the inverse function as:

g(x)  = - x/2 + 2.5

Now we need to see which pairs belong to this line. I just will evaluate the function g(x) in different values of x, and see which points belong to the line.

g(9) = -9/2 + 2.5 = -4.5 + 2.5 = -2

(9, -2) belongs to the line.

g(7) = -7/2 + 2.5 = -3.5 + 2.5 = -1

Then (7, -1) belongs to this line.

g(5) = -5/2 + 2.5 = 0

Then the point (5, 0) belong to this line.

We can already see that all these points are in option B, then option B is the correct one.