Symbolic Constants - HP -28S Manual

Equations as Data. When you calculate with equations, such as
adding two equations, or squaring an equation, or differentiating an
equation, the result is another equation. Each side of the equation is
treated independently-each side is an expression treated as data. The
equation maintains its propositional nature, where it holds for only
some values of its variables.
Solving Equations. When you solve an equation numerically, as
you did in "Time Value of Money," you find the value of the
independent variable that satisfies the equality. Similarly, when you
solve an equation symbolically, as you did in "Isolating a Variable" on
page 109, you find an expression which, substituted for the
independent variable, would satisfy the equation.
Symbolic Constants
Algebraics can include the following symbolic constants. These look
like names but are actually functions.
• MINR (minimum real) represents the smallest positive real number.
Its numerical value is 1.00000000000E-499.
• MAXR (maximum real) represents the largest positive real number.
Its numerical value is 9.99999999999E499.
• e represents the base of natural logarithms. Its numerical value on
the HP-28S is 2.71828182846.
• 7r
represents the ratio of circumference to diameter of a circle. Its
numerical value on the HP-28S is 3.14159265359.
• i represents the imaginary number
V=I.
Its numerical value is
(0, 1).
In Numerical Constants mode or Numerical Result mode, evaluation
of symbolic constants returns their numerical values; otherwise,
evaluation returns their symbolic form. (Constants mode and Result
mode are described in chapter 24.)
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