Home » Further Mathematics » The sum, (S_{n}),  of a sequence is given by (S_{n} = 2n^{2} – 5). Find…

The sum, (S_{n}),  of a sequence is given by (S_{n} = 2n^{2} – 5). Find…

The sum, (S_{n}),  of a sequence is given by (S_{n} = 2n^{2} – 5). Find the 6th term.

  • A.
    112
  • B.
    67
  • C.
    45
  • D.
    22
Correct Answer: Option D
Explanation

(S_{n} = 2n^{2} – 5)

(T_{n} = S_{n} – S_{n – 1})

(T_{6} = S_{6} – S_{5})

= ((2(6^{2} – 5) – (2(5^{2} – 5) = 62 – 40 = 22)