Register to reply

How to calculate the magnitude of a function?

by seto6
Tags: function, magnitude
Share this thread:
seto6
#1
Apr22-12, 11:25 PM
P: 251
1. The problem statement, all variables and given/known data
I have this function:

G(w)=[itex]\frac{1}{j\omega\tau+1}[/itex]
I want to find the magnitude

2. Relevant equations
S=[itex]\alpha[/itex]+j[itex]\beta[/itex]

magnitude(S)=[itex]\sqrt{[itex]\alpha[/itex]^{2}+[itex]\beta[/itex]^{2}}[/itex]


[b]3. The attempt at a solution[/b

What i did was carry out the division,

so i got
[itex]\frac{j\omega\tau-1}{-(j\omega+1)}[/itex]
then do i just split it into real and imaginary part and then take the magnitude using this?
S=[itex]\alpha[/itex]+j[itex]\beta[/itex]

magnitude(S)=[itex]\sqrt{[itex]\alpha[/itex]^{2}+[itex]\beta[/itex]^{2}}[/itex]

Can anyone help i am not so sure how to approach this?
Phys.Org News Partner Science news on Phys.org
Study links polar vortex chills to melting sea ice
Lab unveil new nano-sized synthetic scaffolding technique
Cool calculations for cold atoms: New theory of universal three-body encounters
failexam
#2
Apr23-12, 12:56 AM
P: 339
Quote Quote by seto6 View Post
What i did was carry out the division,

so i got
[itex]\frac{j\omega\tau-1}{-(j\omega+1)}[/itex]
This is where you got it wrong. Try to multiply the numerator and the denominator of the original G(ω) by [itex] - j ω \tau + 1[/itex] and see what you get.
failexam
#3
Apr23-12, 01:01 AM
P: 339
Then, try and think what you had to multiply by the expression [itex]- j ω \tau + 1 [/itex] to get your answer.

Ray Vickson
#4
Apr23-12, 01:52 AM
Sci Advisor
HW Helper
Thanks
P: 5,091
How to calculate the magnitude of a function?

Quote Quote by seto6 View Post
1. The problem statement, all variables and given/known data
I have this function:

G(w)=[itex]\frac{1}{j\omega\tau+1}[/itex]
I want to find the magnitude

2. Relevant equations
S=[itex]\alpha[/itex]+j[itex]\beta[/itex]

magnitude(S)=[itex]\sqrt{[itex]\alpha[/itex]^{2}+[itex]\beta[/itex]^{2}}[/itex]


[b]3. The attempt at a solution[/b

What i did was carry out the division,

so i got
[itex]\frac{j\omega\tau-1}{-(j\omega+1)}[/itex]
then do i just split it into real and imaginary part and then take the magnitude using this?
S=[itex]\alpha[/itex]+j[itex]\beta[/itex]

magnitude(S)=[itex]\sqrt{[itex]\alpha[/itex]^{2}+[itex]\beta[/itex]^{2}}[/itex]

Can anyone help i am not so sure how to approach this?
Failexam's suggestions are all you need to do. However, if you are going to use LaTeX, why not do it properly? Your expression for "magnitude(S)" is ugly; here is what it should look like: [itex]\text{magnitude}(S)=\sqrt{\alpha^2 + \beta^2}.[/itex] To get this, just remove the "inner" [i t e x]-[/i t e x] pairs; furthermore, if you want the word "magnitude" to appear in nice text font, just include it inside the [i t e x] command, but say \text{magnitude}.

RGV
RoshanBBQ
#5
Apr23-12, 02:54 AM
P: 280
The magnitude of two vectors divided is the division of the magnitudes. What is the magnitude of the numerator? What is the magnitude of the denominator? What is the result of dividing those magnitudes?


Register to reply

Related Discussions
How to calculate vector angles and magnitude Introductory Physics Homework 12
Need to calculate the magnitude of the initial velocity? Calculus & Beyond Homework 1
Need to calculate the magnitude of the initial velocity? Introductory Physics Homework 1
Calculate magnitude of spring force Introductory Physics Homework 8
Calculate the magnitude of buoyant force Introductory Physics Homework 1