Math Problem Statement

What is the range of the function f(x) = 2x^2 + 2 over the interval of -2 ≤ x < 5?

Solution

Let's analyze the function provided in the image:

Function:

f(x)=2x2+2f(x) = 2x^2 + 2

Interval:

The function is defined over the interval 2x5-2 \leq x \leq 5.

Steps to find the range:

  1. Since this is a quadratic function 2x2+22x^2 + 2, the graph will be a parabola opening upwards (because the coefficient of x2x^2 is positive).
  2. To find the range, we need to check the values of f(x)f(x) at the boundaries of the interval and the vertex of the parabola, since the vertex will give us the minimum value (as the parabola opens upwards).

Finding the vertex:

The vertex of a parabola in the form f(x)=ax2+bx+cf(x) = ax^2 + bx + c is given by the formula: xvertex=b2ax_{vertex} = -\frac{b}{2a} For f(x)=2x2+2f(x) = 2x^2 + 2, a=2a = 2 and b=0b = 0, so: xvertex=02(2)=0x_{vertex} = -\frac{0}{2(2)} = 0 Thus, the vertex occurs at x=0x = 0.

Evaluating the function at key points:

  • At x=2x = -2: f(2)=2(2)2+2=2(4)+2=8+2=10f(-2) = 2(-2)^2 + 2 = 2(4) + 2 = 8 + 2 = 10
  • At x=5x = 5: f(5)=2(5)2+2=2(25)+2=50+2=52f(5) = 2(5)^2 + 2 = 2(25) + 2 = 50 + 2 = 52
  • At the vertex, x=0x = 0: f(0)=2(0)2+2=2f(0) = 2(0)^2 + 2 = 2

Conclusion:

  • The minimum value of the function occurs at x=0x = 0 and is f(0)=2f(0) = 2.
  • The maximum value of the function occurs at x=5x = 5 and is f(5)=52f(5) = 52.

Range:

Thus, the range of f(x)f(x) over the interval 2x5-2 \leq x \leq 5 is: 2f(x)522 \leq f(x) \leq 52

Answer:

The correct choice based on the options provided is: 10f(x)<5210 \leq f(x) < 52


Would you like more details or have any questions?

Here are some related questions to explore:

  1. How do you determine the direction of a parabola?
  2. What is the effect of increasing the coefficient of x2x^2 on the range of the function?
  3. How can we find the vertex of a parabola if the bb-term is non-zero?
  4. What are the general properties of quadratic functions?
  5. How does changing the interval affect the range of a quadratic function?

Tip: Always evaluate the function at the endpoints and vertex when finding the range of quadratic functions over a closed interval.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Interval Notation

Formulas

Quadratic function: f(x) = ax^2 + bx + c
Vertex of a parabola: x_vertex = -b / (2a)

Theorems

Range of a Quadratic Function

Suitable Grade Level

Grades 10-12