Math Problem Statement

Suppose that the function fis defined for all real numbers as follows. f(x) = 6 if x < - 4; - 10 + x ^ 2 if - 4 <= x < 4; 2x - 2 if x >= 4 Find the points to graph

Solution

To graph the piecewise function f(x)f(x), we need to consider the function's definition over the three intervals specified:

  1. For x<4x < -4:
    f(x)=6f(x) = 6.

    • Here, the function is a horizontal line at y=6y = 6 for all xx values less than 4-4.
    • There is no specific endpoint at x=4x = -4 because x=4x = -4 is not included in this interval.
  2. For 4x<4-4 \leq x < 4:
    f(x)=10+x2f(x) = -10 + x^2.

    • This is a quadratic function (a parabola) that opens upwards.
    • The endpoint at x=4x = -4 is included, so f(4)=10+(4)2=10+16=6f(-4) = -10 + (-4)^2 = -10 + 16 = 6.
    • The endpoint at x=4x = 4 is not included, so we will only evaluate the function at values close to but less than x=4x = 4. For instance, f(0)=10+02=10f(0) = -10 + 0^2 = -10 and f(3.9)=10+3.925.21f(3.9) = -10 + 3.9^2 \approx 5.21.
  3. For x4x \geq 4:
    f(x)=2x2f(x) = 2x - 2.

    • This is a linear function with a slope of 2 and a y-intercept of 2-2.
    • The endpoint at x=4x = 4 is included, so f(4)=2(4)2=82=6f(4) = 2(4) - 2 = 8 - 2 = 6.

Summary of Key Points:

  • The graph is a horizontal line at y=6y = 6 for x<4x < -4.
  • The graph is a parabola y=10+x2y = -10 + x^2 between x=4x = -4 and x<4x < 4, starting at (4,6)( -4, 6 ).
  • The graph is a straight line with equation y=2x2y = 2x - 2 for x4x \geq 4, starting from (4,6)(4, 6).

Points to Graph:

  1. (4,6)(-4, 6) (included)
  2. (4,6)(4, 6) (included)
  3. Additional points for the parabola, e.g., (0,10)(0, -10), (3.9,5.21)(3.9, 5.21)
  4. For x4x \geq 4, the line can continue to points like (5,8)(5, 8), (6,10)(6, 10), etc.

Would you like more details or have any questions?

Here are 5 related questions:

  1. How would you determine the vertex of the parabola in the piecewise function?
  2. What happens to the continuity of the function at x=4x = -4 and x=4x = 4?
  3. How would the graph change if the function for x4x \geq 4 was 2x+22x + 2 instead?
  4. How does the derivative of f(x)f(x) behave across the different intervals?
  5. What would the graph look like if the quadratic portion was x210xx^2 - 10x instead?

Tip: When sketching piecewise functions, pay special attention to whether endpoints are included or excluded in each interval to ensure accurate graphing.

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Math Problem Analysis

Mathematical Concepts

Piecewise functions
Quadratic functions
Linear functions

Formulas

None

Theorems

None

Suitable Grade Level

High School