Posted by **Wayne** on Thursday, November 11, 2010 at 9:22pm.

Use the method of differences to prove the following formulas

1) ∑_(r=1)^n▒〖r=(n(n+1))/2〗

2) ∑_(r=1)^n▒〖r^2=(n(n+1)(2n+1))/6〗

## Answer this Question

## Related Questions

- mathematics - ∫▒dx/(x√(2x^2+5x+1)) 2. ∫▒dx/(x&#...
- Math - Mathematical Induction - 3. Prove by induction that∑_(r=1)^n▒...
- College Alegbra - Prove by mathematical induction: ∑_(i=1)^n▒〖...
- College Alegbra - Find the sum of the infinite geometric series given by ∑...
- chemistry - 1. Divide the ions below into 2 groups, those that tend to form ...
- Physics - Coefficient of volume expansion of some liquids(a/˚C) Alcohol=1....
- Physics - Coefficient of volume expansion of some liquids(a/˚C) Alcohol=1....
- calculus - Find the trigonometric integral (a) ∫▒tan〖...
- Physics - Coefficient of volume expansion of some liquids(a/˚C) Alcohol=1....
- math engineering - ) ∫_(-1)^2 ∫_0^6▒〖x² sin(x-y)...

More Related Questions