Question

Write the sum using summation notation, assuming the suggested pattern continues. 729 + 1000 + 1331 + 1728 + ... + n3

Answer 1

Ans: $\sum_9^n n^3$


Following is the expression to denote the above-mentioned series:

$\sum_9^n n^3$

Where n = integer.

As:
9^3 = 729
10^3 = 1000
11^3 = 1331
and so on.
-i

Answer 2

Each term of the sum is n^3
The first term of the sum is 729, then:
n^3=729
cubic root (n^3)=cubic root (729)
n=9, then the first term of the sum is for n=9

Then the sum is:
Sum from k=9 to n of k^3
\sum\limits^n_9 {k^{3} }\