Which of the following equations represents the graph?
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 is E
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