Your is wrong . . .
Each term is divided by 3: .Calculate the sum of the geometric series: .
The first term of a geometric series is a and the second is ar. Here, a= 99, alright, but (99)(3) is NOT 33. Your r is wrong. 99r= 33 so what is r?
Oh, blast! Soroban got in 5 minutes before me. I need to learn to type faster!
Yeah. I was told that. Why is that, though? Why does this formula not work for ? How could we calculate the sum if or r ?For another, along with that formula for the sum of an infinite geometric series, you should have learned that it is only valid for
, of course. Thanks.The first term of a geometric series is a and the second is ar. Here, a= 99, alright, but (99)(3) is NOT 33. Your r is wrong. 99r= 33 so what is r?
The infinite GP formula actually came from this :
Now , as n approaches infinity
Consider this : and .. which is approaching 0 ? It would be right . That's why in order for to be 0 , the has to first be 0 which would only happen if . If this condition isn't applied , then it would approach infinity instead of 0 .