# trying out LATEX

• Mar 21st 2009, 05:44 PM
manyarrows
trying out LATEX
$\int$ x dx = $\frac{x^2}{2}$+C
• Mar 23rd 2009, 06:03 PM
lmk866
This is what must be typed: $$\int x ~dx = \frac{x^2} {2} + C$$

the "~" adds a space. alternatively, you can use "\," or "\;"
• Mar 23rd 2009, 06:40 PM
Reckoner
It is probably best to include the whole expression in one set of  tags. lmk866 has it.

Quote:

Originally Posted by lmk866
the "~" adds a space. alternatively, you can use "\," or "\;"

\, is the one that is typically used for this purpose. The other two give a bit more space:

$a\,a$: $$a\,a$$
$a~a$: $$a~a$$:
$a\;a$: $$a\;a$$
• Apr 27th 2009, 10:21 PM
fardeen_gen
Test
\sum\limits_{n = 0}^{ \infty } {\frac{1}{n!}\left[\sum\limits_{k = 0}^{n} {(k + 1)\left(\int_0^1 2^{-(k + 1)x}\ dx\right)\right]8}}

This isn't working! Why?

EDIT:
Thanks Opalg! Also, eight shouldn't be there.
• Apr 28th 2009, 02:58 AM
Opalg
Quote:

Originally Posted by fardeen_gen
\sum\limits_{n = 0}^{ \infty } {\frac{1}{n!}\left[\sum\limits_{k = 0}^{n} {(k + 1)\left(\int_0^1 2^{-(k + 1)x}\ dx\right)\right]8}}

This isn't working! Why?

I don't know why, but for some reason the compiler doesn't like the unnecessary braces that you have used to wrap around some sections of the formula. Remove the red ones in this code
\sum\limits_{n = 0}^{ \infty } {\frac{1}{n!}\left[\sum\limits_{k = 0}^{n} {(k + 1)\left(\int_0^1 2^{-(k + 1)x}\ dx\right)\right]8}}
and you get $\sum_{n = 0}^{ \infty } \frac{1}{n!} \left[\sum_{k = 0}^{n}(k + 1)\left(\int_0^1 2^{-(k + 1)x}\, dx\right)\right]8$

(And it looks as though the 8 probably shouldn't be there at all?)

Also note that you don't need to use \limits with \sum. They are supplied automatically.
• Apr 29th 2009, 04:56 PM
lmk866
i am not exactly sure about the equation you are trying to write but here are the syntax problems

correct form
\sum_{n = 0}^{\infty} {\frac{1}{n!} \left[ \sum_{k = 0}^{n} {(k+1)\left( \int_{0}^{1} 2^{-(k + 1)x} dx \right)} \right]}

problems
1 - \dx
2 - the location of closed }

note: you can eliminate the \limits. \sum_{lowerbound}^{upperbound} works

i hope this helps..
• Apr 29th 2009, 05:00 PM
chella182
The .pdf file in this thread is really helpful for LaTex codes I find :)
• Aug 31st 2009, 10:01 AM
edutabacman
how about this $\frac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}$ here, or

$\frac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}$

like this?
• Aug 31st 2009, 10:02 AM
edutabacman
well, \n $\frac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}$\n
eh?
• Aug 31st 2009, 10:05 AM
edutabacman
or, better
$\frac{{n!}}{{r!\left( {n - r} \right)!}}$
like $\frac{{n!}}{{r!\left( {n - r} \right)!}}$this?
• Aug 31st 2009, 10:08 AM
edutabacman
but
$\begin{array}{*{20}{c}}
{\sqrt {{b^2} - 4ac} } & {\frac{1}{2}} \\
{\mathop {\lim }\limits_{x \to \infty } \frac{1}{x} = 0} & {\sum\limits_{i = 0}^\infty {{x_i}} } \\
\end{array}$
• Aug 31st 2009, 10:09 AM
edutabacman
$\left[ {\begin{array}{*{20}{c}}
{\sqrt {{b^2} - 4ac} } & {\frac{1}{2}} \\
{\mathop {\lim }\limits_{x \to \infty } \frac{1}{x} = 0} & {\sum\limits_{i = 0}^\infty {{x_i}} } \\
\end{array}} \right]$
• Aug 31st 2009, 10:40 AM
edutabacman
but <latex>$\left[ {\begin{array}{*{20}{c}} {\sum\limits_{i = 1}^n {{X_i}{Y_i}} } & {\frac{{x - \mu }}{\sigma }} \\ {\frac{{{\partial ^2}\Omega }}{{\partial u\partial v}}} & {\sqrt {{b^2} - 4ac} } \\ \end{array}} \right]$</latex>
• Aug 31st 2009, 10:41 AM
edutabacman
I know
$\left[ {\begin{array}{*{20}{c}}
{\sum\limits_{i = 1}^n {{X_i}{Y_i}} } & {\frac{{x - \mu }}{\sigma }} \\
{\frac{{{\partial ^2}\Omega }}{{\partial u\partial v}}} & {\sqrt {{b^2} - 4ac} } \\
\end{array}} \right]$

right?