10. Series

Question 1

n
Σ r
r=1

Answer 1

1/2 n(n+1)

Question 2

n
Σ r²
r=1

Answer 2

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

Question 3

n
Σ r³
r=1

Answer 3

1/4 n²(n+1)²

Question 4

Σ

Answer 4

means the sum of

kind of acts like a for loop

Question 5

Σ(u + c)

Answer 5

equal to Σu + Σc

Question 6

Σcu

Answer 6

equal to cΣu

Question 7

n
Σc
r=1

Answer 7

equal to nc