Finding the Vertex of a Function

Oct 13, 2025 by wbrum.org 14 views

In mathematics, the vertex of a function is a crucial concept that helps us understand the behavior of the function. It is the point at which the function changes from increasing to decreasing or vice versa. In this article, we will explore the concept of the vertex of a function and how to find it for a given function.

What is the Vertex of a Function?

The vertex of a function is the point at which the function reaches its maximum or minimum value. It is the turning point of the function, where the function changes from increasing to decreasing or vice versa. The vertex is an important concept in mathematics, as it helps us understand the behavior of the function and make predictions about its future values.

Finding the Vertex of a Function

To find the vertex of a function, we need to use the concept of the vertex form of a quadratic function. The vertex form of a quadratic function is given by:

f(x) = a(x - h)^2 + k

where (h, k) is the vertex of the function. To find the vertex, we need to complete the square and rewrite the function in vertex form.

Completing the Square

Completing the square is a technique used to rewrite a quadratic function in vertex form. It involves adding and subtracting a constant term to the function to create a perfect square trinomial. The constant term is then factored out to reveal the vertex of the function.

Example: Finding the Vertex of f(x) = |x+8|-3

Let's consider the function f(x) = |x+8|-3. To find the vertex of this function, we need to complete the square and rewrite it in vertex form.

f(x) = |x+8|-3

We can start by isolating the absolute value term:

f(x) = |x+8|

Now, we can rewrite the absolute value term as a perfect square trinomial:

f(x) = (x+8)^2 - 64

Now, we can factor out the constant term:

f(x) = (x+8)^2 - 64 + 3

Simplifying the expression, we get:

f(x) = (x+8)^2 - 61

Now, we can see that the vertex of the function is at the point (h, k) = (-8, -61). However, we need to check if this is the correct answer.

Checking the Answer

To check if the answer is correct, we need to plug in the values of x and y into the original function and see if it matches the vertex form of the function.

f(x) = |x+8|-3

Plugging in x = -8, we get:

f(-8) = |-8+8|-3 f(-8) = |-0|-3 f(-8) = 0 - 3 f(-8) = -3

This matches the vertex form of the function, so we can conclude that the vertex of the function is indeed at the point (-8, -3).

Conclusion

In conclusion, the vertex of a function is an important concept that helps us understand the behavior of the function. To find the vertex of a function, we need to complete the square and rewrite the function in vertex form. In this article, we explored the concept of the vertex of a function and how to find it for a given function. We also provided an example of finding the vertex of the function f(x) = |x+8|-3.

Answer

The correct answer is A. $(-8, -3)$ .

References

[1] Khan Academy. (n.d.). Completing the square. Retrieved from https://www.khanacademy.org/math/algebra/x2f6f4d7f:algebra-quadratic-functions/x2f6f4d7f:algebra-quadratic-functions-completing-the-square
[2] Math Open Reference. (n.d.). Vertex form of a quadratic function. Retrieved from https://www.mathopenref.com/quadraticvertexform.html

Understanding the Vertex of a Function
What is the Vertex of a Function?
Finding the Vertex of a Function
Completing the Square
Example: Finding the Vertex of f(x) = |x+8|-3
Checking the Answer
Conclusion
Answer
References
Table of Contents
Vertex of a Function: Q&A ==========================

In our previous article, we explored the concept of the vertex of a function and how to find it for a given function. In this article, we will answer some frequently asked questions about the vertex of a function.

Q: What is the vertex of a function?

A: The vertex of a function is the point at which the function reaches its maximum or minimum value. It is the turning point of the function, where the function changes from increasing to decreasing or vice versa.

Q: How do I find the vertex of a function?

A: To find the vertex of a function, you need to complete the square and rewrite the function in vertex form. The vertex form of a quadratic function is given by:

f(x) = a(x - h)^2 + k

where (h, k) is the vertex of the function.

Q: What is the vertex form of a quadratic function?

A: The vertex form of a quadratic function is given by:

f(x) = a(x - h)^2 + k

where (h, k) is the vertex of the function.

Q: How do I complete the square?

A: Completing the square is a technique used to rewrite a quadratic function in vertex form. It involves adding and subtracting a constant term to the function to create a perfect square trinomial. The constant term is then factored out to reveal the vertex of the function.

Q: What is the difference between the vertex and the axis of symmetry?

A: The vertex and the axis of symmetry are related but distinct concepts. The axis of symmetry is a line that passes through the vertex of the function and is perpendicular to the x-axis. The vertex is the point at which the function reaches its maximum or minimum value.

Q: Can the vertex of a function be a maximum or a minimum?

A: Yes, the vertex of a function can be a maximum or a minimum. If the function is concave up, the vertex is a minimum. If the function is concave down, the vertex is a maximum.

Q: How do I determine if the vertex of a function is a maximum or a minimum?

A: To determine if the vertex of a function is a maximum or a minimum, you need to examine the concavity of the function. If the function is concave up, the vertex is a minimum. If the function is concave down, the vertex is a maximum.

Q: Can the vertex of a function be a point of inflection?

A: Yes, the vertex of a function can be a point of inflection. A point of inflection is a point at which the function changes from concave up to concave down or vice versa.

Q: How do I find the vertex of a function with a negative leading coefficient?

A: To find the vertex of a function with a negative leading coefficient, you need to complete the square and rewrite the function in vertex form. The vertex form of a quadratic function with a negative leading coefficient is given by:

f(x) = a(x - h)^2 + k

where (h, k) is the vertex of the function.

Q: Can the vertex of a function be a complex number?

A: Yes, the vertex of a function can be a complex number. If the function has a complex root, the vertex may be a complex number.

Q: How do I find the vertex of a function with a complex root?

A: To find the vertex of a function with a complex root, you need to complete the square and rewrite the function in vertex form. The vertex form of a quadratic function with a complex root is given by:

f(x) = a(x - h)^2 + k

where (h, k) is the vertex of the function.

Conclusion

In conclusion, the vertex of a function is an important concept that helps us understand the behavior of the function. We have answered some frequently asked questions about the vertex of a function and provided examples of how to find the vertex of a function.

References

[1] Khan Academy. (n.d.). Completing the square. Retrieved from https://www.khanacademy.org/math/algebra/x2f6f4d7f:algebra-quadratic-functions/x2f6f4d7f:algebra-quadratic-functions-completing-the-square
[2] Math Open Reference. (n.d.). Vertex form of a quadratic function. Retrieved from https://www.mathopenref.com/quadraticvertexform.html

Understanding the Vertex of a Function
What is the Vertex of a Function?
Finding the Vertex of a Function
Completing the Square
Example: Finding the Vertex of f(x) = |x+8|-3
Checking the Answer
Conclusion
Vertex of a Function: Q&A
Q: What is the vertex of a function?
Q: How do I find the vertex of a function?
Q: What is the vertex form of a quadratic function?
Q: How do I complete the square?
Q: What is the difference between the vertex and the axis of symmetry?
Q: Can the vertex of a function be a maximum or a minimum?
Q: How do I determine if the vertex of a function is a maximum or a minimum?
Q: Can the vertex of a function be a point of inflection?
Q: How do I find the vertex of a function with a negative leading coefficient?
Q: Can the vertex of a function be a complex number?
Q: How do I find the vertex of a function with a complex root?
Conclusion
References
Table of Contents