Turn on thread page Beta
 You are Here: Home >< Maths

# Integrate a curve watch

1. I have the curve. I anticipate that there will be a kink/sharp twist in said curve.With the boldened information being the most relevant - how would I solve this integral.So far I have

ds=||AB→||dtds=||AB→||dt

[Although I express doubt and skepticism whether this is right.]Thank you for any help/assistance given.
This is my working out so far. i would appreciate if anyone caould confirm whether I am correct, or assist me please.
2. I'm assuming the curve is supposed to be two line segments. So split the integral up into the two segments (and just add the results for each segment at the end).

For a line from a to b you simply want to parameterize as (x, y, z) = a + t(b - a) (with t going from 0 to 1). So you'll have simple linear functions for x, y, z as functions of t. (E.g. for your segment from (1, 0, 1) to (0, 1, 0) you'd have x = 1 - t, and then you replace dx by ). You'll end up with a simple integral of form

for each segment.

Edit: I haven't really addressed what you've tried to do, because all the stuff with cos and sin seems to be completely irrelevant and I'm not sure what you're actually trying to do.
3. (Original post by DFranklin)
I'm assuming the curve is supposed to be two line segments. So split the integral up into the two segments (and just add the results for each segment at the end).

For a line from a to b you simply want to parameterize as (x, y, z) = a + t(b - a) (with t going from 0 to 1). So you'll have simple linear functions for x, y, z as functions of t. (E.g. for your segment from (1, 0, 1) to (0, 1, 0) you'd have x = 1 - t, and then you replace dx by ). You'll end up with a simple integral of form

for each segment.

Edit: I haven't really addressed what you've tried to do, because all the stuff with cos and sin seems to be completely irrelevant and I'm not sure what you're actually trying to do.

Thank you I changed the parameter to make it in terms of t and I got 1/3 and 34/3 for the two segments.
4. thanks for this ^^^

I thought you left this forum

Your papers got me from a U to an A in M1. Thank you

Turn on thread page Beta

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: October 31, 2016
The home of Results and Clearing

### 4,494

people online now

### 1,567,000

students helped last year
Today on TSR

### IT'S TODAY!

A-level results chat here

### University open days

1. Bournemouth University
Clearing Open Day Undergraduate
Fri, 17 Aug '18
2. University of Bolton
Fri, 17 Aug '18
3. Bishop Grosseteste University
Fri, 17 Aug '18
Poll
Useful resources

## Make your revision easier

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

Can you help? Study help unanswered threads

## Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE