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HOW TO ENTER A PIECEWISE-DEFINED FUNCTION ON TI89 CALCULATOR

Example 1: Function has two(2) parts
Steps Key Sequence Screens
1. Start Equation Editor Press 'diamond' key, then F1 (for Y=)
2. Enter Condition for Equation Press CATALOG key
  Scroll down to
'when(' function
  Press ENTER
(to select
'when(' function
)
  Press X key
  Press 2nd then 5 (for MATH menu)
  Press 8 (TEST submenu)
  Select appropriate test
  Enter x value for condition, then 'COMMA' key
3. Input Function corresponding to this Condition Input function, then press 'COMMA' key
4. Input Other Function Input function, then press ')', then ENTER
5. Select Function Use up arrow key to select function
6. Change Style of Graph Press 2nd, then F1 (to select F6 menu)
  Press 2 (for Dot)
7. Graph Press 'diamond' key, then F3 (for GRAPH)
Example 2: Function has three(3) parts
Steps Key Sequence Screens
1. Input 1st condition and equation Follow steps 1 – 3 above
2. Input 2nd condition and equation Repeat steps 2 & 3 above
NOTE: You are nesting two(2) 'when(' functions!
3. Enter Third Equation Follow step 4 above (the equation MUST end with two(2) parentheses!)
4. Graph Follow steps 5 – 7 above
NOTE: To input compound inequalties use the 'and' found in the CATALOG. That is, to input the condition 1 < x < 2 use: 1 < x and x < 2.