In Week 10 of Pre-Valc we reviewed all of the 4 units to prepare ourselves for the midterm. While reviewing I am strong in understanding the graphing unit since we just convered that and I am confident in solving radical equations, but during my review I paid extra attention to the first unit were we covered arithmetic/geometric sequences and series.

Arithmetic Sequences:

• It is the pattern of the Sequence (adding numbers or subtracting numbers)
• The common difference (d) is the number that the pattern adds or subtracts by
• You can find  by using the formula  = + (n-1)d

Arithmetic Series

• It is the sum of the n terms of a sequance
• You can find the  by using the formula  + ) or  + (n-1)d) if you don’t know the 

Geometric Sequence

• Each of the terms is multiplied by a number, know as the common ratio (r)
• to find  use the formula  = a 

Geometric Series

• It is the sum of the terms
• In a Geometric Series their can be a diverging series with no sum; when a geometric series diverges that means that the numbers are getting bigger
• Or a converging series with a infinite sum; When a geometric series converges that means that the numbers are getting closer together
• To find the  use the fomula  = a (
• To find the  use the formula