In week two of pre-calculus 11, we took similar concepts as in week one . I learned that geometric sequences are sequences which have a multiplying common ratio, rather than a common difference. I also learned how to find the sum of all the terms.

For example – If I want to find a specific term in a geometric sequence, we use the formula :
tn = a (r)n – 1 meaning you multiply the first term (a) by the ratio to the power that is  one less than your term.

I also learned that it is possible to find the sum of all the terms in a never-ending infinite converging series.
The formula can be used if -1<r<1 :
S∞ = a/1 – r