If (f(x) = mx^{2} – 6x – 3) and (f'(1) = 12), find the value of the constant m.
-
A.
9 -
B.
3 -
C.
-3 -
D.
-4
Correct Answer: Option A
Explanation
(f(x) = mx^{2} – 6x – 3)
(f ‘(x) = frac{mathrm d y}{mathrm d x} = 2mx – 6)
(f'(1) = 2m – 6 = 12)
(2m = 18 implies m = 9)