# Riemann Sum question

1. Oct 18, 2006

### Checkfate

Hello, just going through some Riemann sum problems before I hit integrals and I am like 99% sure that this answer from my text is wrong but I want to make sure. It's not really an important question so if you have better things to do, help the next guy :) But checking this over would be appreciated!!

http://img178.imageshack.us/img178/875/incorrectyp5.jpg [Broken]

I am trying to find an approximation of the integral using a Riemann sum.

Here is the question.

http://img216.imageshack.us/img216/2113/incorrect2jj8.jpg [Broken]

Why are they using 32 as the denominators for their endpoints? I have the same numerators but my denominator is 12 since $$\Delta x=\frac{\pi}{6}$$. And for my first midpoint I would use half that.. $$\frac{\pi}{12}$$, and then add delta x again n times, right?

Last edited by a moderator: May 2, 2017
2. Oct 18, 2006

### StatusX

It's sec(x/3).

3. Oct 18, 2006

### Checkfate

Sigh, how dumb of me... thanks, arg!

If I had f()'s around my fractions I would have been fine, forgot about that. :( Thanks though, and sorry.

Last edited: Oct 18, 2006