- #1

- 7

- 0

**Please Help,urgent**

i have a trigonometry question and i really dont know how to solve i checked couple of books but still no hope here it is:

im supposed to draw the graph of y=cos¶/3(x-1) but i couldnt

so please help..

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter özge
- Start date

- #1

- 7

- 0

i have a trigonometry question and i really dont know how to solve i checked couple of books but still no hope here it is:

im supposed to draw the graph of y=cos¶/3(x-1) but i couldnt

so please help..

- #2

Tom Mattson

Staff Emeritus

Science Advisor

Gold Member

- 5,549

- 8

Is it supposed to be this:

[tex]

y=cos(3x-1)

[/tex]

or this:

[tex]

y=cos(\frac{1}{3x-1})

[/tex]

?

- #3

arildno

Science Advisor

Homework Helper

Gold Member

Dearly Missed

- 10,025

- 134

y=cos¶/3(x-1)???????????????????????????????????????????????????özge said:i have a trigonometry question and i really dont know how to solve i checked couple of books but still no hope here it is:

im supposed to draw the graph of y=cos¶/3(x-1) but i couldnt

so please help..

Neither can I. Please type in the CORRECT formula.

- #4

Lisa!

Gold Member

- 620

- 96

I think it's something else!Tom Mattson said:

Is it supposed to be this:

[tex]

y=cos(3x-1)

[/tex]

or this:

[tex]

y=cos(\frac{1}{3x-1})

[/tex]

?

- #5

- 7

- 0

y=cos pi/3(x-1)

now ok?

now ok?

- #6

arildno

Science Advisor

Homework Helper

Gold Member

Dearly Missed

- 10,025

- 134

[tex]y=\cos(\frac{\pi}{3x-1})[/tex]

Hints:

1. Find the point of singularity, where y is not defined.

2. Determine the set of points were y is -1, 0, 1 respectively.

In particular, see what this implies for the function's behaviour very close to the singularity found in 1.

- #7

- 7

- 0

ok it is not that y is equal to cos multiplied by pi/3 multiplied by (x-1)

- #8

Tom Mattson

Staff Emeritus

Science Advisor

Gold Member

- 5,549

- 8

What you have written is this:

[tex]y=cos(\frac{\pi}{3x-1})[/tex].

Now that's a perfectly legitimate function, but I strongly suspect that it is not the one you are supposed to graph, simply because it's too difficult for a trigonometry course. I am inclined to think that you really meant this:

[tex]y=cos[\frac{\pi}{3}(x-1)][/tex].

Am I right?

- #9

- 7

- 0

(x-1) isnt near 3

- #10

Tom Mattson

Staff Emeritus

Science Advisor

Gold Member

- 5,549

- 8

I don't know what that means.

- #11

arildno

Science Advisor

Homework Helper

Gold Member

Dearly Missed

- 10,025

- 134

özge:

If Tom Mattson is right, here's how you could have written this properly:

y=cos(pi*(x-1)/3)

If Tom Mattson is right, here's how you could have written this properly:

y=cos(pi*(x-1)/3)

- #12

- 7

- 0

Tom Mattson said:

What you have written is this:

[tex]y=cos(\frac{\pi}{3x-1})[/tex].

Now that's a perfectly legitimate function, but I strongly suspect that it is not the one you are supposed to graph, simply because it's too difficult for a trigonometry course. I am inclined to think that you really meant this:

[tex]y=cos[\frac{\pi}{3}(x-1)][/tex].

Am I right?

u are right

- #13

Tom Mattson

Staff Emeritus

Science Advisor

Gold Member

- 5,549

- 8

özge said:ok it is not that y is equal to cos multiplied by pi/3 multiplied by (x-1)

This can't be right. cos without an argument makes no sense.

- #14

arildno

Science Advisor

Homework Helper

Gold Member

Dearly Missed

- 10,025

- 134

Do you know what the cosine function is??özge said:ok it is not that y is equal to cos multiplied by pi/3 multiplied by (x-1)

What is its argument?

- #15

- 7

- 0

was right im sorry im new to these things and i diddnt know how to write

- #16

Tom Mattson

Staff Emeritus

Science Advisor

Gold Member

- 5,549

- 8

özge said:u are right

Alrighty then!

Here are a couple of tips to get you started.

*Examine the graph of [itex]y=cos(x)[/itex].

*Note that if you have the graph of some function [itex]y=f(x)[/itex] then you can obtain the graph of [itex]y=f(x+a)[/itex] by shifting the graph of [itex]y=f(x)[/itex] horizontally by [itex]a[/itex] units. You move to the right if [itex]a<0[/itex] and to the left if [itex]a>0[/itex].

*The period [itex]T[/itex] of a cosine function [itex]y=A\cos[k(x+a)][/itex] is [itex]T=\frac{2\pi}{k}[/itex].

Give it a shot and see how you do, OK?

- #17

- 7

- 0

ok, thanks

Share: