Checking a proof of the triangle inequality

[Math100]

Homework Statement

Prove 1^2+2^2+...+n^2=(1/6)n(n+1)(2n+1) for all positive integers n.

Relevant Equations

None.

Please check/confirm my work of this proof and tell me if it's correct or not. Thank you.

 

[mjc123]

Your proof is not correct. Your final equation is not equal to the formula for n+1, and you are trying to prove the wrong thing anyway. The series is 1² + 2² +...+ n², not 1 + 2 +...+n.

 

[docnet]

omgursh i love your hand writing