Which of the following equations represents the graph?
-
A.
y = 1 + 2x + 3x2 -
B.
y = 1 – 2x + 3x2 -
C.
y = 1 + 2x – 3x2 -
D.
y = 1 – 2x – 3x2 -
E.
y = 3x2 + 2x – 1
Correct Answer: Option E
Explanation
The roots of the function are 1 and (frac{1}{3})
sum of roots = -1 + (frac{1}{3}) = -(frac{2}{3})
product of roots = -1 x (frac{1}{3}) = -(frac{1}{3})
x2 – (sum of roots)x + (product of roots) = 0
x2 + (-(frac{2}{3}))x – (-(frac{1}{3})) = 0
x2 + (frac{2x}{3}) – (frac{1}{3}) = 0
3x2 + 2x – 1 = 0