HP 33s - Manual (Page 95)

Entering and Evaluating Equations 6–3
Summary of Equation Operations
All equations you create are saved in the equation list. This list is visible whenever
you activate Equation mode.
You use certain keys to perform operations involving equations. They're described
in more detail later.
Key Operation
| H Enters and leaves Equation mode.
‘ Evaluates the displayed equation. If the equation is an
assignment
, evaluates the right–hand side and stores the
result in the variable on the left–hand side. If the equation
is an equality or expression, calculates its value like
X . (See "Types of Equations" later in this chapter.)
X Evaluates the displayed equation. Calculates its value,
replacing "=" with "–" if an "=" is present.
 Solves the displayed equation for the unknown variable
you specify. (See chapter 7.)
|  Integrates the displayed equation with respect to the
variable you specify. (See chapter 8.)
b Begins editing the displayed equation; subsequent
presses delete the rightmost function or variable.
{ c Deletes the displayed equation from the equation list.
™ or š Steps up or down through the equation list.
{j Goes to the top line of the equation or program list.
{h Goes to the last line of the equation or program list.
|  Shows the displayed equation's checksum (verification
value) and length (bytes of memory).
‡ Leaves Equation mode.
You can also use equations in programs — this is discussed in chapter 12.