Math Problem Statement

Graph the function f(x) = -2√(x - 4). Plot four points on the graph of the function: the leftmost point and three additional points.

Solution

The given function to graph is:

f(x)=2x4f(x) = -2\sqrt{x - 4}

Analysis and Key Points:

  1. Domain: The expression under the square root, x4x - 4, must be non-negative. Thus, x40x - 4 \geq 0, which implies x4x \geq 4. The domain of the function is [4,)[4, \infty).

  2. Leftmost Point: The leftmost point is when x=4x = 4. Plugging x=4x = 4 into f(x)f(x):

    f(4)=244=20=0f(4) = -2\sqrt{4 - 4} = -2\sqrt{0} = 0

    So, the point is (4,0)(4, 0).

  3. Additional Points: Let's choose three additional points in the domain x4x \geq 4.

    • Point 1: Let x=5x = 5.

      f(5)=254=21=2f(5) = -2\sqrt{5 - 4} = -2\sqrt{1} = -2 Point: (5,2)(5, -2).

    • Point 2: Let x=8x = 8.

      f(8)=284=24=4f(8) = -2\sqrt{8 - 4} = -2\sqrt{4} = -4 Point: (8,4)(8, -4).

    • Point 3: Let x=12x = 12.

      f(12)=2124=28=242=425.66f(12) = -2\sqrt{12 - 4} = -2\sqrt{8} = -2\sqrt{4 \cdot 2} = -4\sqrt{2} \approx -5.66 Point: (12,5.66)(12, -5.66).

Points to Plot:

  • (4,0)(4, 0)
  • (5,2)(5, -2)
  • (8,4)(8, -4)
  • (12,5.66)(12, -5.66)

You can now use these points to plot the function on the graph.

Would you like more details or have any questions?

Related Questions:

  1. What is the range of the function f(x)=2x4f(x) = -2\sqrt{x - 4}?
  2. How does the graph of f(x)=2x4f(x) = -2\sqrt{x - 4} compare to g(x)=xg(x) = \sqrt{x}?
  3. What are the x-intercepts and y-intercepts of the function?
  4. How does changing the coefficient 2-2 affect the shape of the graph?
  5. What transformations are applied to the parent function y=xy = \sqrt{x}?

Tip: When graphing square root functions, always consider the domain and transformations such as vertical stretching or reflecting.

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Graphing Square Root Functions

Formulas

f(x) = -2√(x - 4)

Theorems

Domain and Range of Square Root Functions

Suitable Grade Level

Grades 9-12