Ok in my Algebra class we are learning about functions and such, and yesterday we learned about inverse variation. So I stumble across this problem in my homework and I have no idea what to do. Here it is:

Directions:
f is the frequency, l is the wavelength, and v is the speed of sound. Use this information in the following problems.

15) The frequency of a note an octave about a given note is twice that of the given note. How does the wavelength of the higher note compare with that of the lower one?

I know for inverse variations I need to do x1 * y1 = x2 * y2 and in direct variation I need to do x1/y1 = x2/y2. The thing is I have no idea what to make of this problem. Is it direct variation? Is it inverse variation? "The frequency of a note an octave about a given note is twice that of the given note"... does this mean I need to write 2f+1 = f? Since its twice that of the given note (2f) and is an octave above a given note (+1). Then it tells me "How does the wavelength of the higher note compare with that of the lower one?"... does this mean I have to set up a proportion? If I were to set up a proportion would that mean the problem is a direct variation problem? And if I have to set up a proportion, how do I do it with the given information?
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Buuuh I could answer this using physics, but I don't think you're meant to do that.

Your working seems very obfuscated to me, I can't really see what you're trying to do.

The frequency of the second note is twice the frequency of the first note
Frequency is inversely proportional to wavelength so doubling the frequency?? The wavelength.

(edited to not give away the answer)