Determine X for Positive Values in the Quadratic Equation y = 3x² - 6x + 4

Question

Look at the following function:

y=3x26x+4 y=3x^2-6x+4

Determine for which values of x x the following is true:

f\left(x\right)>0

Step-by-Step Solution

To solve the problem, we'll follow these steps:

  • Step 1: Solve the quadratic equation 3x26x+4=0 3x^2 - 6x + 4 = 0 using the quadratic formula.
  • Step 2: Determine the intervals based on the roots and analyze the sign of the quadratic in each interval.
  • Step 3: Use the results to conclude for which values of x x the quadratic is positive.

Step 1: The quadratic formula yields the roots:

x=b±b24ac2a,x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}, where a=3 a = 3 , b=6 b = -6 , and c=4 c = 4 .

Calculating the discriminant:

b24ac=(6)2434=3648=12 b^2 - 4ac = (-6)^2 - 4 \cdot 3 \cdot 4 = 36 - 48 = -12 .

Since the discriminant is negative (12-12), the quadratic equation has no real roots. This means the parabola does not intersect the x-axis, and the entire graph is above or below it.

Step 2: Since a=3 a = 3 (positive), the parabola opens upwards. A quadratic function with no real roots and a positive leading coefficient will be entirely above the x-axis, indicating it is always greater than zero.

Step 3: Since it is positive across all x x -values, the solution is:

The function is positive for all x x .

Answer

The function is positive for all x x .