Graphing Radical Functions: Examples


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Graphing Radical Functions: Examples (page 2 of 3)

Graph

First I'll find the domain by finding where the argument is non-negative:

Then I'll find some plot points:

T-chart

Finally, I'll do the graph:

y = -sqrt(3x - 2)

Graph

First I'll find the domain by finding where the argument is non-negative:

Then I'll find some plot points:

T-chart

I picked x-values that gave me nice neat y-values. Other x-values will work just as well; the choice is up to you.
Copyright © Elizabeth Stapel 2006-2008 All Rights Reserved

Now I'll do the graph:

y = 2sqrt(4x + 1) + 3

Graph

I'll first find the domain: I have to solve the quadratic inside the square root; it may be easier just to look at the graph of the quadratic.

In this case, x² + 1 is always above the x-axis (that is, it is always positive), so x can be anything; there is no restriction on the domain of the square root.

y = x^2 + 1

Then I'll find some plot points:

I used a calculator to approximate the y-values to three decimal places. This is more than sufficient for graphing.

T- chart

Finally, I'll do the graph:

y = sqrt(x^2 + 1)

Note that, unlike an absolute value graph, this graph does not have an "elbow" at the bottom; it is curved. Don't go too quickly when graphing; take the time to notice details like this.

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Cite this article as:

Stapel, Elizabeth. "Graphing Radical Functions: Examples." Purplemath. Available from
http://www.purplemath.com/modules/graphrad2.htm. Accessed

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