Thursday, May 12, 2016

Daily Regents: Graphing a Square Root Function

I'll be reviewing a New York State Regents Exam Question every day from now until the Regents exams begin next month. At least, that is the plan.

June 2014, Question 25

Draw the graph of y = SQRT(x) - 1 on the set of axes below.
As show in the picture, SQRT means "square root", but I can't type that. However, keep that function in mind when we get to the calculator.

Here is what you saw on the paper:

On your graphing calculator, press the "Y=" key. Look at Figure 1 below.
Press "2nd" and "x2" to get the square root symbol and the open parenthesis.
Press the variable and then don't forget to close the parentheses! If you don't close them, then the "- 1" will be under the radical, and that is NOT what you want.
Hit GRAPH and you'll get Figure 2. This is what you need to graph on your paper.

The easiest way to get the values you need is to check the Table of Values. "2nd" and "Graph". Figure 3 and Figure 4 show you are of the coordinate pairs from 0 to 10. Notice that -1 and -2 are ERROR because they are out of the domain of the function. You won't have any line on the left side of the graph.

Plot the four points that have whole number values and draw a curve through them. Do not connect the four point with three straight lines.

Your final answer should look like this:

Any questions?

If anyone in Brooklyn is looking for an Algebra or Geometry Regents Prep tutor, send me a note. I have a couple of weekly spots available between now and June.

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