nth term of -3 + 6 – 12 + 24 – 48 + …………… is A) 2.3n -

1.	nth term of -3 + 6 – 12 + 24 – 48 + …………… is A) 2.3n - 1B) 3.2n + 1 C) (-1)n - 1 . 3.2n - 1 D) (-1)n . 3.2n - 1
Answer» Correct option is (D) \( (-1)^n . 3.2^{n-1}\) Given sequence is -3, 6, -12, 24, -48, ......... \(\Rightarrow-1\times3,(-1)^2\times3\times2,(-1)^3\times3\times2^2,\) \((-1)^4\times3\times2^3,(-1)^5\times3\times2^4,.......\) \(\therefore n^{th}\) term of given sequence is \( (-1)^n\times3\times2^{n-1}\) Correct option is D) (-1)ⁿ . 3.2^{n - 1}

nth term of -3 + 6 – 12 + 24 – 48 + …………… is A) 2.3n - 1B) 3.2n + 1 C) (-1)n - 1 . 3.2n - 1 D) (-1)n . 3.2n - 1

Answer»

Correct option is (D) \( (-1)^n . 3.2^{n-1}\)

Given sequence is -3, 6, -12, 24, -48, .........

\(\Rightarrow-1\times3,(-1)^2\times3\times2,(-1)^3\times3\times2^2,\) \((-1)^4\times3\times2^3,(-1)^5\times3\times2^4,.......\)

\(\therefore n^{th}\) term of given sequence is \( (-1)^n\times3\times2^{n-1}\)

Correct option is D) (-1)ⁿ . 3.2^{n - 1}