HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 103

The evaluation of an equation takes no values from the stack - it uses only numbers in the equation and variable values. The value of the equation is returned to the X-register. The LAST X register isn't affected. Using ENTER for Evaluation If an equation is displayed in the equation list, you can press ‘ to evaluate the equation. (If you're in the process of typing the equation, pressing ‘ only ends the equation - it doesn't evaluate it.) „ If the equation is an assignment, only the right-hand side is evaluated. The result is returned to the X-register and stored in the left-hand variable, then the variable is VIEWed in the display. Essentially, ‘ finds the value of the left-hand variable. „ If the equation is an equality or expression, the entire equation is evaluated - just as it is for X. The result is returned to the X-register. Example: Evaluating an Equation with ENTER. Use the equation from the beginning of this chapter to find the volume of a 35-mm diameter pipe that's 20 meters long. Keys: Display: Description: |H ( ™ as required) ‘ 35 g 20 ‘ 1000 zg 88)  Displays the desired equation. Starts evaluating the assignment equation so the value will be stored in V. Prompts for variables on the right-hand side of the equation. The current value for D is 2.5000. Stores D, prompts for L, whose current value is 16.0000. Stores L in millimeters; calculates V in cubic millimeters, stores the result in V, and displays V. Entering and Evaluating Equations 6-11