Drawing graphical functions? Watch

[email protected]
Badges: 0
#1
Report Thread starter 10 years ago
#1
Hi, this might sound like a really stupid question, but how do I draw a graph for a function like:
f(x) = 1 + cos(2pix) + sin(4pix)

Do I just substitute random values for x.
I need to draw the graph so that I can find out its period.
Thanks
0
reply
Kyalimers
  • PS Reviewer
Badges: 21
#2
Report 10 years ago
#2
yes... or you can get a graphical calculator
reply
mpd1989
Badges: 1
Rep:
?
#3
Report 10 years ago
#3
well, it's easy to see that for any integer x=0,±1,±2, ±3 , ... etc., cos(2πx)=1 and sin(4πx)=0.

So you know that at the integer values of x, f(x)=2

Also at the values x=±0.5, ±1.5, ±2.5 etc. the values are cos(2πx)=-1 and sin(4πx)=0.

So at x=±0.5, ±1.5, ±2.5 etc., f(x)=0 (That's not to say those are the only x values for which this happens)

(If you find this hard to see, note that cos(2π(0.5))=cosπ=-1, and then cos(2πa+b)=cos(b), and a similar thing applies for sine.)

You already have a couple of bits of information about this curve now. Draw in those points and join them up soon...

You will want to differentiate to see where the stationary points are, then you'll be able to draw it. (It actually has four stationary points for each oscillation
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • University of East Anglia
    All Departments Open 13:00-17:00. Find out more about our diverse range of subject areas and career progression in the Arts & Humanities, Social Sciences, Medicine & Health Sciences, and the Sciences. Postgraduate
    Wed, 30 Jan '19
  • Aston University
    Postgraduate Open Day Postgraduate
    Wed, 30 Jan '19
  • Solent University
    Careers in maritime Undergraduate
    Sat, 2 Feb '19

Brexit: Given the chance now, would you vote leave or remain?

Remain (1044)
79.03%
Leave (277)
20.97%

Watched Threads

View All
Latest
My Feed