6-12 Entering and Evaluating Equations
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
. 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.
Using XEQ for Evaluation
If an equation is displayed in the equation list, you can press to evaluate the
equation. The entire equation is evaluated, regardless of the type of equation. The
result is returned to the X–register.
Keys: Display: Description:
( × as required)
π
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 2.5.
Stores D, prompts for L,
whose current value is 16.
Stores L in millimeters;
calculates V in cubic
millimeters, stores the result
in V, and displays V.
Changes cubic millimelers to
liters (but doesn't change V.
