If Solve could not find a solution, you will see one of the following two messages.

Message

Condition

 

 

Bad Guess(es)

The initial guess lies outside the

 

domain of the equation.

 

Therefore, the solution was not a

 

real number or it caused an error.

Constant?

The value of the equation is the

 

same at every point sampled.

 

 

H I N T It is important to check the information relating to the solve process. For example, the solution that the Solve aplet finds is not a solution, but the closest that the function gets to zero. Only by checking the information will you know that this is the case.

The Root-Finder at work

You can watch the process of the root-finder calculating and searching for a root. Immediately after pressing to start the root-finder, press any key except . You will see two intermediate guesses and, to the left, the sign of the expression evaluated at each guess. For example:

+2 2.219330555745

– 1 21.31111111149

You can watch as the root-finder either finds a sign reversal or converges on a local extrema or does not converge at all. If there is no convergence in process, you

might want to cancel the operation (press ) and start over with a different initial guess.

Plotting to find guesses

The main reason for plotting in the Solve aplet is to help you find initial guesses and solutions for those equations that have difficult-to-find or multiple solutions.

Consider the equation of motion for an accelerating body:

=+ AT 2

X V0T 2

Solve aplet

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