Since it is a geometric sequence each term will be a specific multiple of the term preceding it, called the common ratio...
126/42=378/126=1134/378=3
The sequence is a(n)=a(3)^(n-1) and we know the second term is 42 so:
42=a(3)^(2-1)
42=3a
a=14
So the first term is 14.
Answer:
a) the answer if the substitute is 300
Answer: Choice A. 1/64
Work Shown:
f(x) = 4^x
f(-3) = 4^(-3)
f(-3) = 1/(4^3) ... see note below
f(-3) = 1/64
Note: I'm using the rule that a^(-b) = 1/(a^b)
