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HOW TO FIND AN INFLECTION POINT OF A CURVE WITH TI89 CALCULATOR

Steps Key Sequence Screens
1. Input Equation into Y1 Press DIAMOND key, then F1 key (for Y=)
  Type the function
2. Graph Press DIAMOND key, then F3 key
3. Find Inflection Point Press F5
  Press 8 (for Inflection)
  Type in x-value for a point to the left of a suspected inflection point or trace function until you reach the value for x
  Press ENTER
  Type in x-value for a point to the right of a suspected inflection point or trace function until you reach the value for x
  Press ENTER
Note: In this case, the inflection point is (0.666667, 4.40741).