Find the minimum value of X2 – 3x + 2 for all real values of x
-
A.
-(frac{1}{4}) -
B.
-(frac{1}{2}) -
C.
(frac{1}{4}) -
D.
(frac{1}{2})
Correct Answer: Option A
Explanation
y = X2 – 3x + 2, (frac{dy}{dx}) = 2x – 3
at turning pt, (frac{dy}{dx}) = 0
∴ 2x – 3 = 0
∴ x = (frac{3}{2})
(frac{d^2y}{dx^2}) = (frac{d}{dx})((frac{d}{dx}))
= 270
∴ ymin = 2(frac{3}{2}) – 3(frac{3}{2}) + 2
= (frac{9}{4}) – (frac{9}{2}) + 2
= -(frac{1}{4})