This week was AWESOME!!! Monday was my birthday and the stuff we learned all this week was very easy. I hope I still think that when it comes to taking the actual test. We learned about Series of Numbers or something like that. There's two different types, Arithmetic, and Geometric, but if it's neither one of these then it's Neither.
Here's the two formulas:
1. Arithmetic- tn=t1+(n-1)d
n=term # t1=first term d=what you add
2. Geometric- tn=t1*r^(n-1)
r= what you multiply by n=term # t1=first term d=what you add
Ex.
6, 12, 24,.....
this is a Geometric sequence so you would use the formula tn=t1*r^(n-1)
then you would have 6*2^(n-1)
if you wanted to know the 4th term you would plug the 4 into the n and this is what you would get.
6*2^(4-1)
6*2^(3)
6*8
48
The only trouble I think I might have is remembering the formulas in this Chapter.
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well the arithmetic formula and geometric formula is pretty easy to remember.
ReplyDeleteArithmetic: tn=t1+(n-1)d
Geometric: tn=t1-r^(n-1)
and for series:
Arithmetic: Sn=n(t1+tn)/2
Geometric: Sn=t1(1-r^n)/1-r
I know, huh? There's like 12 of them. Any way, I do believe that all of the formulas branch off of the origional geometric and arithmetic formulas. The best thing, I think, to do is as soon as you get your test, write all of your formulas down so you get them out of your head and don't have to focus on remembering them.
ReplyDeleteIt helps a lot.
Good luck.
The formulas are different versions of each other
ReplyDeleteas long as you memorize the first formulas of the chapter the others wont be hard to remember
Arithmetic: tn=t1+(n-1)d
Geometric: tn=t1-r^(n-1)
Arithmetic: Sn= n(t1+tn)/2
Geometric: Sn= t1(1-r^n)/1-r
just find patterns that are easy for you to spot
and rembering the formulas will be easy.