What is the discriminant of 3x1 - 10x = -2

x = 2/7

Step-by-step explanation:

option A. t ≥ 6

Explanation:

The function D = 0.0625t² − 0.75t + 4.25  is a quadratic function; thus, its graph is a parabola.

Since the coefficient of the quadratic term is positive, the parabola opens upward and the vertex is the minimum point of the curve.

That means that the curve decreases, reachs the minimum and then increases.

Then, the demand will increase from the time equal to the x-coordinate (t) of the of the vertex onwards.

Determine the vertex:

The x-coordinate of the vertex of a parabola given by the general form y = ax² + bx + c is equal to -b/(2a).

For D = 0.0625t² − 0.75t + 4.25, b = -0.75 and a = 0.0625, then:

x-coordinate of the vertex = - (-0.75)/(2 × 0.0625) = 6.

Therefore, the demand will increase from the month 6 onwards. That is t ≥ 6 (option A.).