Is everything on this document correct?

Question

quickstudent · Answer

I found this document online about graphing cosine function, but before I read it and start learning I'd like to know if everything on it is correct. document attached

templeguy · Answer

I'll answer this if you answer mine

katherinkoon · Answer

i'm not really sure but i think yes

quickstudent · Answer

How do you tell that fast?

quickstudent · Answer

@mathmale

will.h · Answer

I noticed something not quite sufficient in Question 3 No a when they asked about the domain you should also say that it represents the x values in the functions

will.h · Answer

other than that i hadn't notice anything incorrect.,.

quickstudent · Answer

@AloneS @mathmale @pooja195 @sleepyjess

quickstudent · Answer

@Nnesha

mathmate · Answer

Well done! :)
All correct.  
Perhaps for 3d, you could clarify that the zeroes are x=-270, ...270 within the interval [-360,360].