• Support PF! Buy your school textbooks, materials and every day products Here!

Periodic functions

  • Thread starter Ujjwal28
  • Start date
  • #1
32
0

Homework Statement


What is the fundamental period of the expression sinx/sinx.can you guys please illustrate how to make its graph?

Homework Equations


Okay I know drawing graph can give me the period.Can the period be found by any other method?

The Attempt at a Solution


I'm told that the answer is pi. That is pi radians.I don't know how to sketch it's graph
 

Answers and Replies

  • #2
Math_QED
Science Advisor
Homework Helper
2019 Award
1,397
516
What exactly do you mean? f(x) = sinx/sinx is a constant function without the points for which sinx = 0.
 
  • #3
32
0
It's period is pi that's all I know about it and here is a key the period of cosx/cosx is also pi
 
  • #4
Math_QED
Science Advisor
Homework Helper
2019 Award
1,397
516
what is cosx/cosx equal to?
 
  • #5
RUber
Homework Helper
1,687
344
The definition of a period is the smallest number n such that f(x+n) = f(x), right?
If you look at ##f(x) = \frac{\sin x}{\sin x}## you should see what Math_QED was referring to...for all points where this function is defined, it can be simplified to a constant. However, there are places where the denominator is equal to zero and so f(x) at these points is undefined.
You will notice that there is a regular spacing between these holes in the function. Use that as your period.
 
  • #6
32
0
Okay so you mean y=sinx/sinx will be equal to one but holes will appear at x=0 and pi, 2pi...... npi?
And the spacing bw these holes gives me the period as 1? And same for cos? It will be undefined at npi/2?
 
  • #7
SammyS
Staff Emeritus
Science Advisor
Homework Helper
Gold Member
11,256
974
Okay so you mean y=sinx/sinx will be equal to one but holes will appear at x=0 and pi, 2pi...... npi?
And the spacing bw these holes gives me the period as 1? And same for cos? It will be undefined at npi/2?
No. It gives a period of π .
 
  • #8
32
0
Yeah I got it. It was a typo. Thanks guys and I really loved RUber's answer that made it crystal clear to me thanks bro
 
  • #9
32
0
Okay another question.. What is the lcm of pi, 2pi and pi/3?
 
  • #10
RUber
Homework Helper
1,687
344
Lowest common multiple can't be smaller than the largest member of the group. Check that one first.
 

Related Threads on Periodic functions

  • Last Post
Replies
3
Views
888
  • Last Post
Replies
18
Views
6K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
12
Views
25K
  • Last Post
Replies
6
Views
888
  • Last Post
Replies
7
Views
4K
  • Last Post
4
Replies
78
Views
10K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
11
Views
2K
  • Last Post
Replies
2
Views
2K
Top