The value of the nth term of a sequence is given by the expression a^3n - 3. If the second term of the sequence is 61, wich of the following could be the value of a?
I. -2
II. 2
III. 4
(A) I only
(B) II only
(C) III only
(D) I or II only
(E) II or III only.
2006-11-07 18:19:27 · 4 answers · asked by vutran1512 1 in Education & Reference ➔ Homework Help
a^6-3=61
a^6=64
a^6=64
a=6th rt of 64
a can be or -2
choice i and ii
2006-11-07 18:55:58 · answer #1 · answered by raj 7 · 0⤊ 0⤋
You didn't say if n starts at 0 or 1; it makes a difference in what is meant by "the second term". If n starts at 0, the second term is n=1;that is most common, so that is what I'll assume first
x(n) = a^3n - 3
x(1) = a^3 - 3 = 61
Solve for a^3: a^3 = 61+3 = 64
Then a = cube root of 64 = +4
If by "second term" you mean n = 2,
then
x(2) = a^6 -3 = 61, a^6 = 64 then a = ±2
2006-11-08 02:58:35 · answer #2 · answered by gp4rts 7 · 0⤊ 0⤋
(D) I or II only
2006-11-08 03:53:23 · answer #3 · answered by deansubasinghe 3 · 0⤊ 0⤋
its too complicated for me sorry i am only in hs
2006-11-08 14:31:00 · answer #4 · answered by no longer caligirl. 2 · 0⤊ 0⤋