
1 Attachment(s)
draw cos graph
hi,
i need to draw these on to a graph:
1. Y= cosx
2. Y= cosx+1
3. Y= cos(x+30)
i can do 1 and i think i have done number 2 correct but i can't do number 3.
here is what i have done for number 1 and 2, i have had a go at what i think number 3 would be:
Attachment 20809
i have labled them on the side also.
i think numbers 1 and 2 are correct but if they aren't please let me know and mainly is number 3 correct??
thanks!!!!!

The thing with your drawing of the functions is that you've just drawn straight lines. They should be curves. You should use a program that's a bit better than paint at drawing functions. I myself use graph 4.3. Look the functions up there.
Anyways, it should be like this:
graph one should look like a periodic curve that repeats itself every 360 degrees, i.e. it goes from 1 to 1 on the yaxis after 180 degrees, and then goes back to 1 etc, starting at the point (0,1).
Graph two should look like graph one, except for the fact that it's displaced by 1 in a positive direction on the yaxis.
Graph three should look like graph one also, but should be displaced by 30 degrees to the left.
Best wishes, and good luck with trigonometry!

in my book i have them as curves but i wasn't able to do that on paint because i didn't want to do it free hand! so what i have draw for B or graph 2 is correct??

No, because you have negative values on it. $\displaystyle y = \cos(x) +1$ is the graph of $\displaystyle \cos(x)$ moved up one unit on the y axis which means that while the range it $\displaystyle 0 < \cos(x) + 1 < 2$
For the sake of completion I've added the graphs (in a spoiler). cos(x) is in green, cos(x)+1 is in blue and cos(x+30) is in orange
nb: this graph is in radians (pi/6 = 30 degrees). pi/2 = 90 degrees, pi = 180 degrees, 3pi/2 = 270 degrees and 2pi = 360 degrees

1 Attachment(s)
would this be it then?? (it is labeled 2)
Attachment 20811

Looks fine to me (aside from the technical issues of lines instead of curves of course)