Question

Find the 4th term in the sequence

with the following definition:
a1 = 0
an = 2(an-1 -3)

Answer 1

-42

Explanation:

`a_(1)=0\\a_(n)=2(a_(n-1)-3)\\a_(2)=2(a_(1)-3)=2(0-3)=-6\\a_(3)=2(a_(2)-3)=2(-6-3)=-18\\a_(4)=2(a_(3)-3)=2(-18-3)=-42`