(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find the formula

Σ[n, i =1](2i - 1) = 1+3+5+...+(2n-1)

2. Relevant equations

3. The attempt at a solution

When I look at the back of the book , I got this solution which is

1, Sigma(2i - 1) = 1+3+5+...+(2n-1)

2, = 1+2+3+...+2n-2(1+..+n)

3, = ((2n)(2n+1)) /2 - n(n+1)

4, n^2

What i don't get is what happened from step 1 to 2 and 2 to 3?

It seems that there are hidden steps there that were not written down and therefore and I am really confused about this solution.

Thank you guys very much.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Confused about this answer, michael spivak's calculus

**Physics Forums | Science Articles, Homework Help, Discussion**