Texas Instruments TI-92 Owners Manual - Page 84

Substituting Values and Setting Constraints The "with" operator ( | ) lets you temporarily substitute values into an expression or specify domain constraints. Typing the "With" Operator Substituting for a Variable To type the "with" operator ( | ), press: TI.89: Í TI.92 Plus: 2 Í For every occurrence of a specified variable, you can substitute a numeric value or an expression. First derivative of xìò at x = 5 To substitute for multiple variables at the same time, use the Boolean and operator. Substituting for a Simple Expression Note: acos(x) is different from a*cos(x). For every occurrence of a simple expression, you can substitute a variable, numeric value, or another expression. By replacing a commonly used (or long) term, you can display results in a more compact form. Substituting s for sin(x) shows that the expression is a polynomial in terms of sin(x). Substituting Complex Values You can substitute complex values just as you would for other values. Note: For an overview of complex numbers, refer to Appendix B. Tip: To get the complex i, press 2 ). Do not simply type the letter i on the keyboard. All undefined variables are treated as real numbers in symbolic calculations. To perform complex symbolic analysis, you must define a complex variable. For example: x+yi! z Then you can use z as a complex variable. You can also use z_. For more information see the _ (underscore) topic in Appendix A. Chapter 3: Symbolic Manipulation 67