Feroz's Blog

I'll go over 13-1 since I don't think we did anything else did this week besides tests.

So um, I explained what the difference between arithmetic and geometric was in my last blog, so straight to the formulas.

If it's arithmetic: Tn = T1 + (n-1)d

If it's geometric: Tn = T1 x r^n-1

ex. If Tn = 2n + 1, find the first 4 terms.

T1 = 2(1) + 1 = 3
T2 = 5
T3 = 7
T4 = 9

It is a arithmetic sequence since you're adding two.

ex 2. 3, 8, 13, 18... find the Nth term.

It's arithmetic, so:

Tn = T1 + (n-1)d
= 3 + 5n -5
= 5n -2

That's it.