Limits of integration

Zone Ranger · **Posted:** Fri, 18 Apr 2008 17:10:30 UTC

How do I write

$$\int_a^bf(x)dx$

but with the

and

at the very top and bottom of the integral sign?

Mr.MathType · **Posted:** Fri, 18 Apr 2008 17:24:40 UTC

Zone Ranger wrote:

How do I write

$$\int_a^bf(x)dx$

but with the

and

at the very top and bottom of the integral sign?

Like this:

$$\int\limits_a^b {f(x)dx}$

Instead of \int_a^b, write \int\limits_a^b. Also, the way you constructed your integral, the only thing in the integrand was "f". You should put the entire integrand in braces: {f(x)dx}.

BTW, it's really easy if you're learning LaTeX, to use MathType to construct the equation visually, then let MathType translate it to LaTeX. Of course, if you don't want to learn LaTeX, MathType is a great way to write your equations without having to learn it.

Zone Ranger · **Posted:** Fri, 18 Apr 2008 17:34:39 UTC

Mr.MathType wrote:

... Also, the way you constructed your integral, the only thing in the integrand was "f". You should put the entire integrand in braces: {f(x)dx}....

$$\int_a^bf(x)dx$ $$\int_a^b{f(x)dx}$

Code:

[tex]$\int_a^bf(x)dx[/tex][tex]$\int_a^b{f(x)dx}[/tex]

Is there supposed to be a difference...I don't see it.

Mr.MathType · **Posted:** Fri, 18 Apr 2008 17:57:56 UTC

Zone Ranger wrote:

Mr.MathType wrote:

... Also, the way you constructed your integral, the only thing in the integrand was "f". You should put the entire integrand in braces: {f(x)dx}....

$$\int_a^bf(x)dx$ $$\int_a^b{f(x)dx}$

Code:

[tex]$\int_a^bf(x)dx[/tex][tex]$\int_a^b{f(x)dx}[/tex]

Is there supposed to be a difference...I don't see it.

The difference isn't in display properties. The difference is mathematical. It's really only a matter of personal preference, and your code wasn't incorrect. In fact, in the book "LaTeX Line by Line" by Antoni Diller, the integral examples are exactly like yours. I should have stated my reason for putting the integrand inside braces, and that's for someone reading the code rather than looking at the "built-up" expression. It's just easier to look at and tell what's part of the integrand and what isn't. In a simple expression like your example, it's easy to tell even without the braces. In more complex integrals, it's not so easy.

Another reason to put the integrand inside braces is if the code is pasted into software that is able to interpret the LaTeX mathematically (like MathType 6), there's no ambiguity in the interpretation.

Rather than saying "you should put the entire integrand in braces", a better way for me to have responded would have been to say "if you put the integrand in braces, it reduces the possibility for ambiguity when translating into other software languages (such as MathML), or for interpretation by software products (like MathType)". To imply that your LaTeX markup was incorrect was inadvertent on my part.

Zone Ranger · **Posted:** Fri, 18 Apr 2008 17:58:38 UTC

Mr.MathType wrote:

Like this:

$$\int\limits_a^b {f(x)dx}$

Instead of \int_a^b, write \int\limits_a^b.

thanks

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Limits of integration

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