How do you find the sum of the series #12i# from i=0 to i=5?

1 Answer
Jan 21, 2017

You can add #12(0) + 12(1) + 12(2) + 12(3) + 12(4) + 12(5)#, or recognize a pattern and apply a formula.

Explanation:

What type of sequence is #0, 12, 24,36, 48, 60#?
If it is arithmetic, then we have a nice formula to apply!
Turns out that it is arithmetic, with a first term #a_1# = 0, #a_6=60# and d = 12, with n = 6 terms.

#S_6=6/2(0+60)# = 3*60 = 180.