Education Technology

# Knowledge Base

## Solution 11759: Graph of the Absolute Value of the Square Root of X Differs on the TI-83 Family, TI-84 Plus C Silver Edition, or TI-84 Plus Family Graphing Calculator and on the TI-89 Family, TI-92 Family, and Voyage™ 200 Graphing Calculators.

### Why does the graph of the absolute value of the square root of x differ on the TI-83 family, TI-84 Plus C Silver Edition, or TI-84 Plus family and on the TI-89 family, TI-92 family, and Voyage 200?

If a TI-83 family, TI-84 Plus C Silver Edition, or TI-84 Plus family calculator is in real mode when solving for the absolute value of the square root of a negative number, the message ERR:NONREAL ANS is displayed.

This is because an intermediate answer, the square root of a negative number, is imaginary. If the TI-83 family, TI-84 Plus C Silver Edition, or TI-84 Plus family calculator is set to one of its imaginary modes, the unit will return the same answer as the TI-89 family, TI-92 Family, and Voyage 200.

The TI-89 family, TI-92 family, and Voyage 200 do not require that the intermediate results be real, only that the final result be real.

Graphs of the function in imaginary and real modes will differ based on the calculation requirements of the TI-83 family, TI-84 Plus C Silver Edition, or TI-84 Plus family calculator. If the calculator is set to real mode, the graph of only the positive x values will be displayed. With the calculator in one of the imaginary modes, both the positive and negative values of x are displayed.

For more information regarding your Texas Instruments graphing calculator, please refer to the guidebooks section.