This week in pre calculus 11 we learned the other half of our sequence and series, we introduced geometric sequences, we learned that each term is multiplied by a constant, known as the common ratio like in the past week with series it was called the common difference. Tn-1 means the term in front of Tn.

The equation for geometric sequences that we learned was: and i learned that r could never equal 1

For me a trick that helped is instead of writing the a1 at the top of the formula i would replace it with t1 because for me looking at the equation it makes more sense because they mean the same thing, i also like to write the common ratio as: CR instead of r so it in my mind it doesn’t look like a variable for a number.

We also learned about finite geometric series which is different from geometric sequences for example

3,13,48,192: is a geometric sequence

3+12+48+192 is a geometric series

In some of the question to find the answers we had to go back to the week before and use the formulas that we learned from the past week using the equation for tn first and then using our new sn equation