Find Multiple Solutions with the TI-84 Plus
Some equations can have more than one solution. You can easily find multiple solutions on your TI-84 Plus. If you’re dealing with an absolute value equation or an equation with a degree larger than one, there’s a good chance the equation will have multiple solutions.
Using the Equation Solver, you can employ one of two techniques to find multiple solutions to equations.
When you expect multiple solutions, guess a large positive number as your first guess. This strategy typically produces the largest solution for the equation you’re solving. The first screen is the result of guessing 100.
After you find one solution, guess the opposite of the large positive number as your second guess. Many times, this technique will find the smallest solution. In the second screen, the guess was –100 for the second guess.
The result of guessing –100 is pictured in the third screen. Depending on the equation, it may be necessary to continue guessing until you find all the solutions to the equation.
An E1–E2 value of zero indicates an exact solution. The third screen shows a solution that is off by the extremely small number (–1.1*10-11).