x|y

0=-8
1=-7 1/2
2=-7
3=-6 1/2
Which equation describes the function shown in the mapping diagram?

1 answer

To derive a linear equation from the given mapping data, we can first convert the points from the mapping into ordered pairs:

  • (0, -8)
  • (1, -7.5)
  • (2, -7)
  • (3, -6.5)

Next, we need to determine the slope (m) of the line that fits these points. The slope can be calculated using the formula:

\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]

Using the first two points (0, -8) and (1, -7.5):

\[ m = \frac{-7.5 - (-8)}{1 - 0} = \frac{0.5}{1} = 0.5 \]

Now, we can use the slope-intercept form of the equation of a line, which is given by:

\[ y = mx + b \]

where \(m\) is the slope and \(b\) is the y-intercept. We already found that \(m = 0.5\). To find \(b\), we can substitute one of the points into the equation. Using the point (0, -8):

\[ -8 = 0.5(0) + b \implies b = -8 \]

Now we can write the equation of the line:

\[ y = 0.5x - 8 \]

So, the equation that describes the function shown in the mapping diagram is:

\[ y = 0.5x - 8 \]