In this section, square root inequalities will be solved using the table on a calculator. A calculator is needed for this section.

Solve using a graphing calculator.

Enter the information into your calculator as if you were going to graph the two sides of the inequality as separate functions under Y1 and Y2.

Create a table:

graphing calculator screen showing a table of values for X, Y1, and Y2 from x = -2 to x = 4. Y1 is labeled y = sqaure root of (3x + 3) and Y2 is labeled y = 3. Values for y < 3, y = 2 and y > 3 are indicated.

Just like when you look for the parts of the graph that were above and below y = 3, you need to compare the two y-columns. Look for where the y-coordinate in the square root function is above, below, and equal to 3.

graphing calculator screen showing a table of values for X, Y1, and Y2 from x = -2 to x = 4. Y1 is labeled y = square root of (3x + 3) and Y2 is labeled y = 3.  Values for y < 3, y = 2 and y > 3 are indicated.

Click on the blanks to reveal the answers

Why does it say “ERROR” in the Y1 column for x = - 2? Interactive button. Assistance may be required. __________ If you substitute in any x-value less than -1, you will get an imaginary number which is not in the domain of the square root function.

Which colored area contains the solutions? Interactive button. Assistance may be required. __________ Yellow

Why? Interactive button. Assistance may be required. __________ The inequality symbol is < and the yellow area shows I-values that are less than 3.

How do you know that x cannot be less than -1? Interactive button. Assistance may be required. __________ When x = -1, then y = 0. If x < -1, then the radicand becomes negative which makes the y-value imaginary.

Is -1 included in the solution set? Interactive button. Assistance may be required. __________ Yes

Why or why not? Interactive button. Assistance may be required. __________ When you substitute x = -1 in, you get 0 < 3, which is true

Is 2 included in the solution set? Interactive button. Assistance may be required. __________ No

Why or why not? Interactive button. Assistance may be required. __________ Because the inequality is <. It would be included if it was ≤

What is the solution to the inequality? Interactive button. Assistance may be required. __________ -1 ≤ x < 2

graphing calculator screen showing a table of values for X, Y1, and Y2 from x = -2 to x = 4. Y1 is labeled y = square root of (3x + 3) and Y2 is labeled y = 3.  X-values from x = -1 to x = 2 are circled.