Question

What is the sum of the arithmetic series? Can someone explain this it's confusing me quite a bit.
(Will post equation)

Answer 1

\[\sum_{t = 1}^{18} (3t - 4)\]

Answer 2

The formula for the first n terms of an arithmetic sequence, starting with n = 1, is:
\[\sum_{i=1}^{n}a_i = (n/2) (a_1+a_n)\] So plug-in and solve.
\[(18/2)(-1+50)= 9*49=441\]

Answer 3

Thanks, I get that now.. Do you know about the sum of finite geometric series?

Answer 4

Yea, one sec.

Answer 5

\[\sum_{k=0}^{n-1}ar^k = a * ((1-r^n)/(1-r))\]

Answer 6

For\[\sum_{ = 0}^{15} 2(1/2)^{x}\] Does that mean:
\[2(\frac{ 1 - 1/2^{15} }{ 1 - 12 }) \] Is that the right way to set it up?

Answer 7

I would think so. That makes sense.

Answer 8

Thanks a lot!