Jump to content

Sum of A.S

martianxx
in Mathematics

Featured Replies

I had a question in a recent exam that asked you to prove the formula to calculate the sum of an A.S. I only got 2/11 on it so i was wondering if someone could tell me it. I have searched the internet for one but all seem to be a bit rubbish and i think i can get better results here :)

The nice thing about arithmetic sequences is that the "average" of all the numbers in the sequence is just the average of the first and last numbers. That is, if the sequence {a1, a2, ..., an} is an arithmetic sequence, then

(a1+ a2+ ... + an)/n= (a1+ an)/2. And so the sum, a1+ a2+ ... an is just that average (a1+a2)/2 times n.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Configure browser push notifications
Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.