i have math homework and cant figure out what to do
Neither can anybody here, unless you share with us exactly what you've been asked to do.
i dont know how to label f(m) -f(m)
You can label f(m) minus f(m) zero.
Or is your typing supposed to be a list (missing all of the commas)?
f(m), -f(m), f(-m)
Who know ? Certainly nobody here.