Math looks so pretty, all
nicely formatted in the textbook. But when you go to e-mail your instructor
with a question, or post your question to a math tutoring forum, you can
end up with a mess or with something that totally doesn't mean what you
meant to say. To deal with this issue, the math community is developing
norms for text-only formatting. What follows is not "the" one
right way to format math, but is a distillation of what I've seen a lot
of math tutors use.
4 ÷ 2
4/2 4 ÷ 2
The "slash" is commonly
used to indicate division or fractions, but you can also insert
the "divided by" sign (on a PC) by holding down the "ALT"
key and typing "0247" on the numeric keypad.
4 × 2
4 * 2 4 × 2 (4)(2)
The asterisk is commonly used to
indicate multiplication, but you can insert the "times"
sign (on a PC) by holding down the "ALT" key and typing
"0215" on the numeric keypad.
(1/2)x + 5
Without the parentheses around the
"one-half", it will be unclear whether or not the variable
is meant to be included in the denominator.
1/(2x) + 5
The variable isn't often in the denominator
like this, so use parentheses to make it clear where the variable
1/(2x + 5)
The parentheses make it clear that
the "five" is included in the denominator.
Without the parentheses, it would
not be clear that the first "x"
belongs inside the numerator, or that the "5x
+ 6" belongs inside the
(x + 2)/(x^2 + 5x + 6)
Use different grouping symbols to
demark the two fractions within the complex fraction. Using extra
spaces is helpful, too.
[(x + 3)/5] / [(x - 4)/2]
The carat key, usually "shift-6"
on the keyboard, is customarily used to indicate exponents.
Without the parentheses, it will
look like you mean "x
squared, divided by three".
Without the parentheses, it will
look like you mean "two cubed, times x",
when you actually mean the variable to be in the exponent.
x^2 y^3 z^4
Use spacing to make clear where one
factor (and its exponent) ends and the next begins.
Yes, this is clunky notation, but
the tutors will understand that you mean "f-inverse
(f o g)(x) f(g(x))
Either use a lower-case O to indicate
function composition, spacing things out so it doesn't look like
you're trying to spell "fog", or else switch from "f-compose-g
notation to "f
Piecewise functions are one of the
few items for which multi-line formatting is pretty-much inescapable.
Just do the best you can.
The abbreviation "sqrt"
stands for "the square root of", and the parentheses make
it clear that both the "2"
and the "y"
belong inside the radical.
The abbreviation "cbrt"
stands for "the cube root of", and the parentheses make
it clear that the "7"
is inside the radical, but the "x"
For larger-index roots, give the
value of the index, and explain your notation. In this case, you
would say "I'm using '5th-rt()' to stand for 'the fifth root
Write out "greater than or equal
to" just as you say it: a "greater than" sign followed
by an "equals" sign.
Write out "less than or equal
to" just as you say it: a "less than" sign followed
by an "equals" sign.
~ = (approx)
The "wiggly equals" means
"approximately equal to", and indicates that you've rounded.
You can either use the tilde (the single wiggly line, probably close
to the "ESC" key) or a regular "equals" sign
followed by the notation "(approx)", indicating that the
answer is an approximate value. If you use the tilde, say what you
mean by it.
!= =/= <>
The exclamation mark is commonly
used in computer programming to mean "not", so "!="
means "not equal". But the "equals-slash-equals"
sequence more closely simulates the "not equal to" symbol.
The "less than, greater than" sign is also sometimes used,
but not so commonly. Whichever you use, define in your post what
you mean by the notation.
You can use "+/–", or you
can enter the character directly (on a PC) by holding down the "ALT"
key and typing "0177" on the numeric keypad.
x1 x_1 x
Subscripting doesn't come up much,
and it's a pain when it does. Many people just put the subscript
after the variable, but this can be confused with superscripting.
The underscore is handy, but if you're dealing with very complicated
expressions, you might want to use the bracketing notation. Define
what you mean ("x-sub-one")
in your post.
Use the underscore to indicate the
base, and use parentheses to make clear what is inside the log.
Do not use a capital "I"
for the natural log. The notation is "LN" (ell-enn), not
"IN" (eye-enn). And don't forget your parentheses.
log_2(y) log_10(y) log_e(y)
If you use just plain "log(y)",
the base will be unclear. Either use the underscore notation to
state the base, or else define yourself. Depending on the context,
a plain "log", without a base noted, will be assumed to
have a base of 2,
or of e.
Don't assume the tutor knows which one you mean.
The square can go right on the function,
but this can sometimes get a bit confusing, especially if your log
has a base notation on it. In messy cases, put the exponent outside
the function, using brackets (so the power goes on the log, and
not just the log's argument).
You can use "abs()" to
indicate absolute value (or "modulus"). But you should
be able to enter the absolute bars into your post by using the "pipe"
character. Look for a key somewhere above the "Enter"
key with a shift character that looks like a broken line. It will
type as a solid line.
If you must use multi-line
formatting (rather than the single-line formatting demonstrated above),
then use especial care in formatting. (This would apply to such things
as polynomial long division or synthetic division.) If you're e-mailing
your question, then compose the post using a fixed-width font such as
Courier, and warn the recipient that he'll need to view the post in a
fixed-width font. If you're posting to a message board, use "PRE"
tags, if allowed, or else format using the "CODE" tags (or something
similar). And remember to "Preview" your post before actually
posting it to the message board, so you can make sure that your post clearly
says what you mean it to say.
Use standard abbreviations,
or none at all. For instance, "m" means "meters" (though
it could also, depending on the context, mean "slope"); if you
mean "miles", use "mi". If you're not sure of the
abbreviation, spell it out; if you want to invent your own abbreviation,
that's find, but define yourself clearly. For instance, if you're working
with rational expressions, don't just say "i cant find HA";
instead, say "I'm having trouble finding the horizontal asymptote
One note on variables:
Don't change the case in the middle of your post. In math, a capital "X"
and a lower-case "x"
are not the same thing. If you change, willy-nilly, back and forth between
cases, you'll have the tutor wondering if you really mean two different
variables. If you mean only one variable, then use only one name for it.