How Do I Get The Theta Sign On My TI-84?
Theta (θ) is the eighth letter of the Greek alphabet and a symbol commonly used in math. It doesn't have a specific meaning, but is used as a substitute variable with angles and polar coordinates. Basically, its meaning changes depending on the context in which it is used. If you're struggling to find the theta sign on your TI-84 Plus graphing calculator, don't worry. It's definitely there — it's just not immediately obvious.
1. Turn on Your TI-84
Press the On key on your TI-84 calculator. An information box will appear. Press the 1 key to continue to the home screen and not see the information box the next time you turn it on, or press the 2 key to simply continue to the home screen.
2. Set Polar Mode
To get the theta sign, your TI-84 calculator needs to be in Polar mode. Press the Mode key (near the top of the keyboard). By default, the TI-84 is in Normal mode. To set Polar mode, press the downward-pointing triangle key until you get to the line reading "Function Parametric Polar SEQ." Next, press the right-pointing triangle key until Polar is highlighted. Press Enter to select this mode. (In Polar mode, r is a function of θ.)
3. Insert Theta
While your TI-84 is in Polar mode, press the [X,T,θ,n] key (just below the Mode key) to select and insert θ, together with any other characters you require for your expression.