Summation Equations

Question 1

summation of C until n

Answer 1

Cn

Question 2

summation of i until n

Answer 2

n(n+1)/2

Question 3

summation of i^2 until n

Answer 3

n(n+1)(2n+1)/6

Question 4

summation of i^3

Answer 4

n^2(n+1)/4