II. Basic Calculations

B. Calculus Operations

Integration and differentiation operations can be accessed directly on the keypad using the  key. These operations, as well as others, are also accessed via the MATH A: Calculus menu and the menu key F3.

The TI-89 will perform both numerical and symbolic differentiation and integration.

NOTE: If the variable has been assigned a numerical value it must be cleared to perform the symbolic operation.

Example: (a) Find the first derivative of .
(b) Find the second and third derivatives.
(c) Find the value of the first derivative at x=4.

(a) First clear the value of x. Press and . Or use DelVar from the catalog.
Press 8, enter the expression, and .
(b) To find the 2nd derivative, add a 2 after the variable.
To find the 3rd derivative, add a 3 after the variable.
(c) Enter the bar | and x=4 after the expression. The bar | key is below the = key.

Example: (a) Find . Clear the value of x before you perform this calculation.
(b) Evaluate . Show both the exact and an approximate answer.

Press 7, enter the expression, and .
Press 7, enter the expression, the limits of integration, and . Notice that the line is too long for the screen. Use the cursor to scroll over and see the remainder of the screen.
Insert a decimal point after the 4. This will produce a numerical answer.