**Tony @ Tue Dec 10, 2013 2:45 am wrote:**

You need to actually solve for the value of f(n-1). But you already know what it is!

If f(n) = n^2 + 2m * f(n-1)

then f(n-1) = (n-1)^2 + 2m * f(n-2)

which you can put back into the original equation.

f(n) = n^2 + 2m * ((n-1)^2 + 2m * f(n-2))

etc. Keep going until you remove f() from the right side of the equation, then simplify.

not sure how to "keep going and simplify". The third equation would be:

f(n) = n^2+2m[(n-1)^2+2m(n-1)^2+4m^2f(n-3)], .... what exactly would be the i'th case? I don't see a pattern here.. and why is this equation so tedious? Is this the right way to do a multiple choice question worth 1 mark on a 100 mark 3 hour final exam? Because I would probably get 0% on the final then haha