Submitted by Maths12345 on Mon, 05/29/2017 - 14:30

I am doing part (i) but I cannot get the answer to come out to be the soln. I keep getting 3/2(n-1) but the answer is supposed to be 3/2n(n-1)

I simplified the integral to just be the 3 times the integral of x - floor(x) between n and 1 and calculated that as (n-1) * area of a unit triangle * 3 but this doesn't get me the correct answer.

What am I doing wrong?

Thanks and sorry I don't know how to format this properly

## I'm pretty sure that's a typo

I'm pretty sure that's a typo. I also got $\frac{3}{2}(n-1)$ by the same method as you.