# Thread: how do I get my TI-89 to solve for this equation?

1. ## how do I get my TI-89 to solve for this equation?

How do I get my Ti-89 to solve 2cosx+1=0
and cos^3x=cosx ? Any help will be apreciated.

2. Press F2 and then 'solve'.

Here's a screen capture from my TI-92. It works the same.

The @n1 symbol represents a constant we can call c.

If you enter an integer value for this, then we have a solution which satisfies the equation.

If c=0, then we have $\displaystyle \frac{2\pi}{3}, \;\ \frac{-2\pi}{3}$

If c=1, then we have $\displaystyle \frac{8\pi}{3}, \;\ \frac{4\pi}{3}$

and so forth.

3. ## hmmm

how do I change the constant?

4. Originally Posted by SRGTLORD
how do I change the constant?
Do you want to use numbers instead of @n1 ? If so:

1. Place the cursor into the line with the results: The results are marked up
2. Press ENTER: The line is copied into the edit line
3. Now you can alter every entry in this line

### srgtlord

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