Find the coordinates of the point on the curve (y = x^{2} + 4x – 2), where the gradient is zero.
-
A.
(-2, 10) -
B.
(-2, 2) -
C.
(-2, -2) -
D.
(-2, -6)
Correct Answer: Option D
Explanation
(y = x^{2} + 4x – 2)
(frac{mathrm d y}{mathrm d x} = 2x + 4 = 0)
(2x = -4 implies x = -2)
(y(-2) = (-2^{2}) + 4(-2) – 2 = 4 – 8 – 2 = -6)
(therefore (x, y) = (-2, -6))