HP 35s Scientific Calculator - Manual (Page 103)

Entering and Evaluating Equations 6-1
6
Entering and Evaluating Equations
How You Can Use Equations
You can use equations on the HP 35s in several ways:
For specifying an equation to evaluate (this chapter).
For specifying an equation to solve for unknown values (chapter 7).
For specifying a function to integrate (chapter 8).
Example: Calculating with an Equation.
Suppose you frequently need to determine the volume of a straight section of pipe.
The equation is
V = .25
π
d 2 l
where d is the inside diameter of the pipe, and l is its length.
You could key in the calculation over and over; for example,
 calculates the
volume of 16 inches of 2 1 /
2
–inch diameter pipe (78.5398 cubic inches). However,
by storing the equation, you get the HP 35s to "remember" the relationship between
diameter, length, and volume — so you can use it many times.
Put the calculator in Equation mode and type in the equation using the following
keystrokes: