Variables & Functions
Variables start with letters and can also contain numbers:
(It’s best to start with lowercase letters, reserving capitals for built-in objects.)
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A space between two variables or numbers indicates multiplication:
(In other words, “a b” is a times b, whereas “ab” is the variable ab.)
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Use /. and to make substitutions in an expression:
(The “rule” can be typed as ->.)
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Assign values using the = symbol:
Use your variable in expressions and commands:
Clear the assignment, and x remains unevaluated:
Define your own functions with the construction f[x_]:=
x_ means that x is a pattern that can have any value substituted for it.
:= means that any argument passed to f is substituted into the right-hand side upon evaluation:
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QUICK REFERENCE: Defining Variables and Functions »
