Operations:  Pi, i, and e

Pi, i, and e are all numeric values that can be accessed using the calculator keys.
Pi

1.   The Pi key is 2nd- ^.              
2.   Use it in expressions as if it were a number like any other.   The advantage of using the pi key over entering 3.14 is the rounding error introduced by entering 3.14.
3. Press the Y= key.
   
   
4. 
   
   i
   The i key is at the bottom of the calculator.  Press 2nd-decimal point.
     i is the square root of -1   and leads to work with complex numbers.  The Ti-83 will do complex number arithmetic as well as real number calculations.
   
   
   
   
   
   
   
   When dividing, use the MATH-FRAC option to give fractional values for A and B in the A + Bi form.
   
   
   

e  

e, like pi, is a constant, irrational number.

To enter e into an expression, press 2nd-division.

If a power of e is needed, use the 2nd-LN keys, then enter whatever power is needed.