Math Problem Statement

Which graph correctly shows the graph of f^(-1)(x), the INVERSE of f(x)?

Solution

The function given is f(x)=x+27f(x) = \sqrt{x + 2} - 7, and we are asked to find which graph represents the inverse of this function, f1(x)f^{-1}(x).

Step 1: Find the inverse of f(x)f(x).

  1. Start with the equation for f(x)f(x): y=x+27y = \sqrt{x + 2} - 7

  2. Swap xx and yy to begin solving for the inverse: x=y+27x = \sqrt{y + 2} - 7

  3. Solve for yy:

    • Add 7 to both sides: x+7=y+2x + 7 = \sqrt{y + 2}
    • Square both sides to remove the square root: (x+7)2=y+2(x + 7)^2 = y + 2
    • Subtract 2 from both sides: y=(x+7)22y = (x + 7)^2 - 2

Thus, the inverse function is: f1(x)=(x+7)22f^{-1}(x) = (x + 7)^2 - 2

Step 2: Analyze the inverse function.

The inverse function f1(x)=(x+7)22f^{-1}(x) = (x + 7)^2 - 2 is a parabola that is shifted 7 units to the left and 2 units down. The parabola opens upward because of the positive square term.

Step 3: Compare the graphs.

  • The correct graph should show a parabola, and the key features to look for are the shift and the direction of the parabola. It should have its vertex at (7,2)(-7, -2) and open upwards.

Conclusion:

Based on the graphs in the image, Graph B correctly represents the inverse function f1(x)=(x+7)22f^{-1}(x) = (x + 7)^2 - 2.

Would you like further details on how the transformation works? Here are five related questions for practice:

  1. How would the graph of f1(x)f^{-1}(x) change if f(x)=x+37f(x) = \sqrt{x + 3} - 7?
  2. What is the domain and range of the inverse function f1(x)f^{-1}(x)?
  3. How do you find the inverse of a function in general?
  4. Can every function have an inverse? Why or why not?
  5. How do the graphs of a function and its inverse relate to each other geometrically?

Tip: A function's graph and its inverse are reflections of each other across the line y=xy = x.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Graph Transformations
Square Root Functions
Parabolas

Formulas

f(x) = sqrt(x + 2) - 7
f^(-1)(x) = (x + 7)^2 - 2

Theorems

Reflection of Function and Inverse across y = x
Properties of Inverse Functions

Suitable Grade Level

Grades 10-12