Originally Posted by

**skeske1234** My question is:

y=7cos[3pi(x-2)]+7

Are my answers correct? Mr F says: I don't know. What are y and x meant to represent? Do you mean wavelength and period in a physical sense? I suppose that in a mathematical sense wavelength and period are the same.

Wave length:

2/3

Period

2/3

__Domain__

**[2, ] ????????????????!**

__What is the second part of it? Can you help?__ Mr F says: Assuming you want the dmain over one period, use the fact that the mathematical period is 2pi/3pi = 2/3 to get the other endpoint of the domain.

Range

[0, 14]

Also, would you describe this cosine function as:

horizontally compressed by a factor of 1/3pi? Mr F says: Horizontal diliation by factor of 1/(3pi).

Ok thanks in advance!