Final answer:
To find the value of x where the function f(x) reaches its minimum, use the vertex formula x = -b/2a. Plugging in the values from the given quadratic function, we find that x = 6.25. Therefore, the correct answer is d. None of the above.
Step-by-step explanation:
To find the value of x where the function f(x) reaches its minimum, we can use the vertex formula which states that the x-value of the minimum or maximum point of a quadratic function in the form f(x) = ax^2 + bx + c is given by x = -b/2a.
In this case, the function f(x) = 4x^2 - 50x + 126 is in the form f(x) = ax^2 + bx + c, where a = 4, b = -50, and c = 126.
Plugging these values into the formula, we get x = -(-50)/(2*4) = 50/8 = 6.25.
Therefore, none of the given options (a, b, or c) correspond to the value of x where f(x) reaches its minimum.
The correct answer is d. None of the above.