Geometric Sequences


In class last week we learned how to calculate geometric sequences using a specific formula and you know that it is a geometric sequence if it has a common ratio and since the equation gave me my common ratio it made it easier to calculate. But some equations the r is unknown and to solve it you have to isolate the variable and then use the ratio number you get and substitute into your formula.

In this geometric sequence I had to determine the S5 by using the tn formula and get the answer. After using the formula I substituted the variables with the numbers in the geometric sequence and then I used my scientific calculator and plugged in the numbers that are in the brackets and then when I got my answer of -968 I had to divide it by a positive 2 since 3-1= +2. Then since I divided a negative with a positive my answer had to become negative due to the exponent rule. It was challenging and confusing at first but then when I worked through more problems I understood how to properly use the formula and what to plug into my calculator to get the right answer. Which now made it easy for me to calculate. The skill checks also very helped me understand how to show my work the right way instead of just messing up in the calculator and getting the wrong answer. Showing my work really helped me because if I messed up on a step then I can no problem go back and check and find out what I did wrong instead of guessing how to get that number.

Ms Burton I am sorry but my blog post didn’t properly post on Friday because shaw turned off my wifi and I had no idea until today in the morning when I decided to check.