Which of the following quadratic equations has (-frac{1}{2}) and (frac{3}{4}) as its roots?
-
A.
8x2 + 11x – 3 = 0 -
B.
8x2 -11x – 3 = 0 -
C.
8x2 + 2x -3 = 0 -
D.
8x2 – 2x – 3 = 0
Correct Answer: Option D
Explanation
X2 – (sum of the roots)x + (product of the roots) = 0
Sum of the roots (= -frac{1}{2}+frac{3}{4} = frac{-2+3}{2}=frac{1}{4})
Product of the roots = (-frac{1}{2}times frac{3}{4}=frac{-3}{8}\
X^2-left(frac{1}{4}right)x-frac{3}{8} = 0. Taking hspace{1mm}thehspace{1mm} common)
(8x^2-2x-3=0);