Home » Further Mathematics » If (f(x) = 3x^{3} + 8x^{2} + 6x + k) and (f(2) = 1), find…

If (f(x) = 3x^{3} + 8x^{2} + 6x + k) and (f(2) = 1), find…

If (f(x) = 3x^{3} + 8x^{2} + 6x + k) and (f(2) = 1), find the value of k.

  • A.
    -67
  • B.
    -61
  • C.
    61
  • D.
    67
Correct Answer: Option A
Explanation

(f(x) = 3x^{3} + 8x^{2} + 6x + k)

(f(2) = 3(2^{3}) + 8(2^{2}) + 6(2) + k = 1)

(implies 24 + 32 + 12 + k = 1)

(68 + k = 1  therefore k = 1 – 68 = -67)