Define Solution Bounds in TI-84's Equation Solver

The bound variable at the bottom of the Equation Solver screen is where you enter the bounds of the interval containing the solution you’re seeking with the TI-84 Plus graphing calculator. The default setting for this interval is [–10⁹⁹, 10⁹⁹], as is indicated by bound = {–1E99, 1E99}. 1E99 is 10⁹⁹ in scientific notation.

The ellipsis at the end of the line containing this variable indicate that you have to repeatedly press

to see the rest of the line.

This default setting is more than sufficient for equations that have a unique solution. So if your equation has a unique solution, you don’t have to do anything with the value in the bound variable.

When the equation you’re solving has multiple solutions, it’s sometimes necessary to redefine the bound variable.

To redefine the bound variable:

1. Use

   

   to place the cursor anywhere in the line containing the bound variable.

2. Press [CLEAR] to erase the current entry.

3. Press [2nd][ ( ] to insert the left brace.

4. Enter the lower bound, press [ . ], enter the upper bound, and then press [2nd][ ( ] to insert the right brace.

5. Press [ENTER] to store the new setting in the bound variable.