Turn on thread page Beta
    • Thread Starter
    Offline

    9
    ReputationRep:
    Hi there..

    I'm attempting to solve this problem

    -pi/2 pi/2 exp(x) δ(cos(2x)) dx

    Ive not seen an example of a delta function before where the argument isnt just an x-x'. For this I thought you'd just set the delta function to 0 giving a value of x=pi/4 or x=-pi/4 but Im not sure how you deal with the fact that there are two acceptable solutions?

    Any help is greatly appreciated.

    Thanks
    Offline

    15
    ReputationRep:
    (Original post by Eremor)
    Hi there..

    I'm attempting to solve this problem

    -pi/2pi/2 exp(x) δ(cos(2x)) dx

    Ive not seen an example of a delta function before where the argument isnt just an x-x'. For this I thought you'd just set the delta function to 0 giving a value of x=pi/4 or x=-pi/4 but Im not sure how you deal with the fact that there are two acceptable solutions?

    Any help is greatly appreciated.

    Thanks
    Look at the Wikipedia article on the delta function.

    It's the section called Composition with a Function
    Offline

    0
    ReputationRep:
    I assume youre referring to this relation?

    Name:  Screen Shot 2017-01-06 at 12.25.48.png
Views: 21
Size:  8.2 KB

    What would xo be in this case though? Is it pi/4 or?

    With there being two solutions (or not if im on the wrong path) am I correct in thinking you sum them to obtain the full answer perphaps?
    Offline

    15
    ReputationRep:
    (Original post by AbbieActon)
    I assume youre referring to this relation?

    Name:  Screen Shot 2017-01-06 at 12.25.48.png
Views: 21
Size:  8.2 KB

    What would xo be in this case though? Is it pi/4 or?

    With there being two solutions (or not if im on the wrong path) am I correct in thinking you sum them to obtain the full answer perphaps?
    The article discusses this and yes it's a sum over the roots.
    Offline

    0
    ReputationRep:
    Oh, my apologies didnt read the next bit down. Thankyou very much for all the help!
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: January 6, 2017
Poll
Favourite type of bread
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

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

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.