Math CentralQuandaries & Queries


Question from Hannah, a student:

Solve y=(1⁄4)x-1 if the domain is (-4,-2,0,2,4).
I don't get how to do this. Can anyone help?

Hi Hannah,

I am going to write

\[y(x) = \frac14 x - 1\]

to stand for the expression $y = \large \frac14 \normalsize x - 1$ evaluated at $x,$ for example $y(3)$ is the value of $y$ when $x = 3.$ thus

\[y(3) = \frac14 \times 3- 1 = \frac34 - 1 = - \frac{1}{4}.\]

In the problem you have the function $y$ has a domain consisting of five points -4, -2, 0, 2, and 4. That is the domain of $y$ is {-4, -2, 0, 2, 4}. The range of the function is then {y(-4), y(-2), y(0), y(2), y(4)}. I think this is what you are expected to find, the range of the function $y$.

I hope this helps. Write back if you need more assistance,

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