How do you find the fifth term in a geometric sequence in which the fourth term is 5, the sixth term is 7, and the common ratio is negative?
hope that helped
The fifth term will be a geometric mean of the fourth and sixth term.
Since the common ratio is negative it will be
The general form of a term of a geometric sequence is:
#a^n = a r^(n-1)#
We are given
Or just taking the geometric mean of
#a_5 = +-sqrt(a_4 * a_6) = +-sqrt(35)#
and we need to use the negative square root to get a negative common ratio.