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Exercises Graphs and straight lines

Example 15 from Algebra and Trigonometry, 4.1 Linear Functions

Finding an x-intercept

Find the x-intercept of $f (x) = \frac{1}{2} x - 3.$

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution
Set the function equal to zero to solve for $x .$

$\begin{matrix} 0 & = & \frac{1}{2} x - 3 \\ 3 & = & \frac{1}{2} x \\ 6 & = & x \\ x & = & 6 \end{matrix}$
The graph crosses the x-axis at the point $(6, 0) .$

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Find the x-intercept of $f (x) = \frac{1}{4} x - 4.$

How did it go?

PreviousMatching Linear Functions to Their Graphs Next Writing the Equation of a Horizontal Line

From Algebra and Trigonometry (1st edition) by OpenStax (Rice University), section 4.1, licensed under CC BY 4.0. Original at openstax.org. We split the solution into steps; the words, numbers and figures are the book's. OpenStax doesn't endorse this site.