Math Problem Statement

Given f(x) = {(-2,1), (0,2), (4,0)} and g(x) = sqrt(9 - x^2), find f(g(x)).

Solution

The problem in the image asks to find f(g(x))f(g(x)), given:

  1. f(x)={(2,1),(0,2),(4,0)}f(x) = \{(-2, 1), (0, 2), (4, 0)\}
  2. g(x)=9x2g(x) = \sqrt{9 - x^2}

Steps:

  1. Evaluate g(x)g(x):
    g(x)=9x2g(x) = \sqrt{9 - x^2} is defined for x[3,3]x \in [-3, 3] (since the square root is only defined for non-negative numbers).

  2. Substitute g(x)g(x) into f(x)f(x):
    The values of f(g(x))f(g(x)) will depend on the output of g(x)g(x), which needs to match one of the input values for f(x)f(x), specifically 2-2, 00, or 44, since those are the only input values where f(x)f(x) is defined.

  3. Solve for specific g(x)g(x) values:

    • g(3)=932=0=0g(3) = \sqrt{9 - 3^2} = \sqrt{0} = 0
    • g(0)=902=9=3g(0) = \sqrt{9 - 0^2} = \sqrt{9} = 3
      This does not match any xx-values in f(x)f(x).
    • g(2)=922=5g(2) = \sqrt{9 - 2^2} = \sqrt{5} (no match in f(x)f(x)).

    The only value that matches is when g(x)=0g(x) = 0, which corresponds to f(0)=2f(0) = 2.

Conclusion:

For values of xx where g(x)=0g(x) = 0, we get f(g(x))=f(0)=2f(g(x)) = f(0) = 2. Thus, f(g(x))=2f(g(x)) = 2 when g(x)=0g(x) = 0.

Would you like further details on this, or any other specific questions about the process?

Here are some related questions:

  1. What is the domain of g(x)=9x2g(x) = \sqrt{9 - x^2}?
  2. How do you compose two functions in general, and what does f(g(x))f(g(x)) represent?
  3. Why does the function f(x)f(x) only give values for x=2,0,4x = -2, 0, 4?
  4. What are the other possible inputs for g(x)g(x) that could simplify f(g(x))f(g(x))?
  5. Can we graph both f(x)f(x) and g(x)g(x) to better visualize their behavior?

Tip: Always check if the values of the inner function are within the domain of the outer function when solving composition problems!

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Math Problem Analysis

Mathematical Concepts

Function Composition
Square Root Function
Piecewise Functions

Formulas

g(x) = sqrt(9 - x^2)
f(g(x))

Theorems

Domain Restriction for Square Root
Function Composition Rule

Suitable Grade Level

Grades 9-12