Math Problem Statement

Determine whether the quadratic function shown below has a minimum or maximum, then determine the minimum or maximum value of the function.

f, of, x, equals, 3, left parenthesis, x, minus, 4, right parenthesis, squared, minus, 7

f(x)=

3(x−4)

2

−7

Solution

The function given is:

f(x)=3(x4)27f(x) = 3(x - 4)^2 - 7

This is a quadratic function in vertex form: f(x)=a(xh)2+kf(x) = a(x - h)^2 + k, where aa, hh, and kk are constants. For this function:

  • a=3a = 3
  • h=4h = 4
  • k=7k = -7

Step 1: Determine if the function has a minimum or maximum

Since a=3a = 3 (a positive number), the parabola opens upwards. This means the function has a minimum value.

Step 2: Find the minimum value of the function

For a function in the form f(x)=a(xh)2+kf(x) = a(x - h)^2 + k, the minimum (or maximum) value occurs at x=hx = h. Here, h=4h = 4.

Now substitute x=4x = 4 into the function to find the minimum value:

f(4)=3(44)27=307=7f(4) = 3(4 - 4)^2 - 7 = 3 \cdot 0 - 7 = -7

Conclusion

The function has a minimum value of 7-7, which occurs at x=4x = 4.

Would you like more details or have any questions?


  1. How do you determine whether a quadratic function has a minimum or maximum value?
  2. Why does the sign of aa in f(x)=ax2+bx+cf(x) = ax^2 + bx + c affect the parabola's direction?
  3. How do we find the vertex of a quadratic function in standard form?
  4. How can we rewrite quadratic functions in vertex form from standard form?
  5. What are real-life examples where minimum or maximum values of a quadratic function are useful?

Tip: The vertex form of a quadratic function makes it easy to identify the maximum or minimum value directly.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Vertex Form

Formulas

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

Theorems

Vertex form of a quadratic function

Suitable Grade Level

Grades 9-10