What is the formula for the #n th# term for the example #6,12,24,48,96?#

please help with finding the pattern for the #n th# term for #6, 12, 24, 48, 96...#

1 Answer
May 21, 2018

#T_n = 6*2^(n-1)#

Explanation:

First establish whether it is arithmetic, geometric or neither,

#d= 24-12 = 12 and d= 12-6 =6" "# it is NOT arithmetic because #d# changes

#r =24div12 = 2 and r= 12div6 =2" "# it is geometric because #r# is the same. Each term is twice the term before it.

The Formula for the general term of a GP is #" "T_n=a r^(n-1)#

We have already found that #r=2#.

#a# is the first term, which is #6#.

Substitute these values into the general formula:

#T_n = 6*2^(n-1)#