## Lukecrayonz 3 years ago Find the nth term of the geometric sequence: a_2 or a[2]=3, a_5 or a[5]=(3/64), n=1

1. Lukecrayonz

@satellite73

2. Lukecrayonz

@bahrom7893 anything? haha

3. Lukecrayonz

I literally know the equation if you have a[1], but nothing when you're solving for a[1]

4. Lukecrayonz

http://screensnapr.com/v/3ZOlWC.png maybe this will help

5. Lukecrayonz

Because the equation while using a[1], is a[n]=a[1]r^(n-1)

6. bahrom7893

a2=a1*r=3; a1=3/r

7. bahrom7893

just do the same thing as the solved example.. or is there a trick somewhere?

8. Lukecrayonz

And solving for r now.. other example doesn't make that much sense to me, and I feel like there is a trick because n-1, 1-1=0.

9. Lukecrayonz

and anything to the power of 0 is 1, so a[1]*1=a[1]..?

10. bahrom7893

r is either powers of 4 or 2..

11. Lukecrayonz

Hmm..?

12. bahrom7893

hang on..

13. bahrom7893

r=1/4, a1=3/1/4=12

14. bahrom7893

a2=3=a1r a1=3/r

15. bahrom7893

a5=a1r^4=a1rr^3=3r^3=3/64

16. bahrom7893

r^3=1/64 r=1/4

17. bahrom7893

a1=3/r=3/1/4=12

18. Lukecrayonz

Got it! Thank you so much haha, stumped me

19. bahrom7893

i don't even know why they give u n, it's totally irrelevant imo

20. Lukecrayonz

Got another question, that literally has nothing to do with anything..

21. Lukecrayonz

Posted it