Which term of the geometric sequence 2,6,18 is 118,098?

1 Answer
Jun 2, 2018

Answer:

#118098# is the #11^(th) term.#

Explanation:

We know that,

#n^(th) term# of geometric seqn. is:

#color(blue)(a_n=a_1(r)^(n-1)#

#where, a_1# is first term and #r# is common ratio.

Here,

Geometric Sequence: #2,6,18,...,118098.#

So,

#a_1=2 , r=6/2=3, and a_n=118098#

#:.a_n=2*(3)^(n-1)=118098#

#=>3^(n-1)=118098/2=59049#

#=>3^(n-1)=3^10#

#=>n-1=10#

#=>n=11#

Hence, #118098# is the #11^(th) term.#