What is the formula for the following geometric sequence? 3, 12, 48, 192, ...
you always multiply a number by 4 so the nswer is 4x where x is greater than 0
an = 4 · 3n - 1 an = 3 · (-4)n - 1 an = 3 · 4n - 1 an = (1/4) · 3n - 1 hmmmmmmmmmmmmmmmmmmmmmmm
this looks strange let me think
mmmm
okay thank you
i not good at secuenses
sorru
the formula for a geometric series is an = a1*r^(n-1) where a1 is the first term in the sequence, and r = common ratio do you know how to find r?
how
r is simply the ratio between the different numbers in the sequence. 3, 12, 48, 192.... You can find r by dividing farthest right number by the one before it 192/48 = 4 48/12 = 4 12/3 = 4 so r = 4
hmmmm. I understand somewhat. lol thank you though
all I did was divide the right term by the one to the left of it starting from 192 Each time, the answer was 4, so that is what r is.
Got it!
cool.
thanks!
any time.
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