I'm a little confused about an assignment:

We have to put functions into a straight line. The most obvious way is to take the log or ln of each side. If the constant is what we are looking for then we need to do this if it is in the exponent.
However if it is not then we can just graph variables to the power of 2 and whatnot. For some reason they come out to a straight line - but I dont understand why. I thought it was because it was a decimal but people are saying that's not right.

I know this sounds confusing so example to clear it up:

T = m(4l^2f^2)
This is a straight line with slope m. but why is it straight - its an exponential function. Is it because frequency is a decimal?

[This is physics btw xD]