How many are in this geometric series? I can't seem to find out. Any help would be appreciated.
3 + 12 + 48 + . . . + 3 * 4^9
I also need help with another problem. The book says the answer is ~20.78meters.
The problem: A ball is dropped from a heigh of 2 meters and bounces up to 90% of its height on each bounce. When it hits the ground for the eighth time, how far has it traveled?
My solution:
I use the theorem from the lesson...
Sn = (G1(1-r^n))/(1-r)
Where Sn is the sum of the first n terms of the geometric sequence with first term g1, and the constant ratio, r, cannot be equal to 1.
... to get
S8 = (2*(1-.9^8)) / (.1).
The equation I have equals to ~11.3 meters, which is wrong. What am I doing wrong?
3 + 12 + 48 + . . . + 3 * 4^9
I also need help with another problem. The book says the answer is ~20.78meters.
The problem: A ball is dropped from a heigh of 2 meters and bounces up to 90% of its height on each bounce. When it hits the ground for the eighth time, how far has it traveled?
My solution:
I use the theorem from the lesson...
Sn = (G1(1-r^n))/(1-r)
Where Sn is the sum of the first n terms of the geometric sequence with first term g1, and the constant ratio, r, cannot be equal to 1.
... to get
S8 = (2*(1-.9^8)) / (.1).
The equation I have equals to ~11.3 meters, which is wrong. What am I doing wrong?
