Identify the 12th term of a geometric sequence where a1 = 8 and a6 = -8,192.

Question

anonymous · Answer

sorry i know they're all the same

anonymous · Answer

same thing 

ar^0 + ar^1

a is 8 

-8192=8*r^5

campbell_st · Answer

then 

using the term in a GP formula

$$a _{n} = a _{1}r^{n -1}$$

$$-8192 = 8r^5$$

solve for r

anonymous · Answer

hmmmm lets see...

campbell_st · Answer

then use the formula above with n = 12

campbell_st · Answer

can you find r..?

campbell_st · Answer

divide both sides by 8

$$r^5 = -\frac{8192}{8} ..... then...... r^5 = -1024$$

anonymous · Answer

mk i got that..... but do u do nething with the ^5?

campbell_st · Answer

$$r = \sqrt[5]{-1024}$$

anonymous · Answer

mmmmmkkkkkkkkk................................ im sorry im lost

campbell_st · Answer

well r = -4

so you now have the information you need 

a = 8 r = -4 and n = 12

substitute it into the formula 

$$a _{n} = a _{1} r^{n -1}$$

anonymous · Answer

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