Question

The \(x\)-coordinate of the vertex is $$ x=\frac{b}{2 a}=\frac{24}{2(4)}=3 $$

Short answer

The x-coordinate of the vertex is 3.

Step-by-step solution

Identifying the values of a and b

In a quadratic equation in the form \(f(x) = ax^2 + bx + c\), co-efficients 'a' and 'b' are given by 4 and 24 respectively.

Calculate the x-coordinate of the vertex

The x-coordinate of the vertex of a quadratic function, given by the formula \(h = -\frac{b}{2a}\), is calculated by substituting 'a' and 'b'. So, the x-coordinate \(h = - \frac{24}{2*4} = 3\).

Key concepts

Understanding the Quadratic Equation

The quadratic equation is a fundamental concept in algebra that describes a curve on a graph called a parabola. A basic quadratic equation is in the form
\[ f(x) = ax^2 + bx + c \],
where a, b, and c are coefficients, and x represents the variable. The coefficient a must not be zero, or the equation would not be quadratic. A noteworthy property of the quadratic equation is its symmetry, which allows us to find its vertex, the highest or lowest point on the parabola, depending on the direction the parabola opens.

When graphing, if a is positive, the parabola opens upwards, and the vertex is the minimum point. Conversely, if a is negative, the parabola opens downwards, and the vertex represents the maximum point. The values of b and c shift the parabola along the x and y axes.

Calculating the X-Coordinate of the Vertex

The vertex of a quadratic function is crucial as it signifies a point of optimal value - either a maximum or a minimum. In the given scenario, the formula used to find the x-coordinate of the vertex is \[ h = -\frac{b}{2a} \.
\] This particular formula derives from the process of completing the square or can be understood as a result of symmetry in the quadratic equation.

To calculate the x-coordinate, one must identify the coefficients from the standard form of the quadratic equation. Then, a simple substitution and arithmetic give us the value of h, which indicates the x-coordinate of the vertex on the graph. In essence, it serves as a line of symmetry for the parabola, and once known, greatly simplifies the process of sketching the curve or solving optimization problems.

Properties of a Quadratic Function

Quadratic functions display a unique set of properties that distinguishes them from other polynomial functions. Besides having a parabolic shape on a graph, quadratic functions have a single vertex that serves as the axis of symmetry, splitting the parabola into two mirror images.

Important Quadratic Function Properties

• The function has a maximum or minimum point at the vertex, depending on the direction of the parabola.
• The axis of symmetry is always a vertical line that passes through the x-coordinate of the vertex.
• The graph will intersect the y-axis at the point (0, c), where c is the constant term of the quadratic equation.
• Depending on the value of the discriminant (b^2 - 4ac), the function may have zero, one, or two real x-intercepts, representing the points where the graph crosses the x-axis.

These properties not only help in graphing the function but also in solving quadratic equations and predicting the nature of the solutions.