Question

Please Help!!
Sequence and Series: Show that the sequence 8, 4√2, 4, 2√2, ... is geometric. Hence find, in simplest form, the general term Un.

Answer 1

What do you know of geometric series? :)

Answer 2

i know hw to do it; i just cant simplify it enough to get the right answer.
so far i have:
u1=8 and r = 1/√2
so the equation i have right now is Un = 8(1/√2)^n-1
I don't know how to simplify it further.
The real answer is completely different.

Answer 3

Is the answer
\[\huge u_n=8\cdot2^{\frac{1-n}2} \]?

Answer 4

no it is \[u_{n}=2^{\frac{ 7 }{ 2 } - \frac{ n }{ 2 }}\]

Answer 5

The book also says that my values for u1 and r are correct then i dont know what is wrong with my equation

Answer 6

Well, of course :)
\[\huge u_n=8\cdot2^{\frac{1-n}2}=2^3\cdot 2^{\frac{1-n}2}=2^{3+\frac{1-n}{2}}\]

Answer 7

o i see...
omg. Thank you so much @PeterPan :)