Which graph represents the function f(x) = -x^2 + x …

Mathematics Questions

Which graph represents the function f(x) = -x^2 + x + 6?

Short Answer

The function f(x) = -x^2 + x + 6 is a downward-opening parabola with its vertex at (1/2, 11/4). The x-intercepts, found by solving the equation f(x) = 0, are at x = 2 and x = 3, which help in accurately sketching the graph.

Step-by-Step Solution

Step 1: Understand the Shape of the Graph

The function f(x) = -x^2 + x + 6 represents a downward-opening parabola. This is determined by the negative coefficient of the x^2 term, indicating that the graph will peak at its vertex. The vertex is a critical point that represents the highest value of the graph.

Step 2: Calculate the Vertex

To find the vertex, use the vertex formula x = -b/(2a). Here, the values are:

  • a = -1 (coefficient of x^2)
  • b = 1 (coefficient of x)

Plugging these into the formula gives:

  • x-coordinate: 1/2

By substituting this x value back into the function, we find that the vertex is at the point (1/2, 11/4).

Step 3: Find the X-Intercepts

The x-intercepts occur where the graph crosses the x-axis, meaning we set f(x) = 0. Solving the equation -x^2 + x + 6 = 0 using the quadratic formula yields:

  • x = 2
  • x = 3

These intercepts, along with the vertex, enable you to sketch the graph accurately, showing a downward parabola peaking at the vertex and crossing the x-axis at these two points.

Related Concepts

Function

A mathematical relation in which each input has a single output, often expressed as f(x), where x is a variable.

Vertex

The highest or lowest point on a parabola, representing the maximum or minimum value of the quadratic function.

X-Intercept

The point where a graph intersects the x-axis, found by setting the function equal to zero and solving for x.

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