Math Problem Statement

Give the inverse of the following functions: g(x) = (x - 5) / (x + 4), f(x) = 4(x - 5) + 3, f(x) = 6√(x - 9), h(x) = (2x - 1) / x, m(x) = x - 5 + 1.

Solution

Let's work through each of the functions in the image to find their inverses step by step.

1. g(x)=x5x+4g(x) = \frac{x - 5}{x + 4}

To find the inverse:

  • Replace g(x)g(x) with yy:
    y=x5x+4y = \frac{x - 5}{x + 4}
  • Swap xx and yy (since we're finding the inverse):
    x=y5y+4x = \frac{y - 5}{y + 4}
  • Solve for yy:
    1. Multiply both sides by y+4y + 4:
      x(y+4)=y5x(y + 4) = y - 5
    2. Expand:
      xy+4x=y5xy + 4x = y - 5
    3. Group all terms involving yy on one side:
      xyy=4x5xy - y = -4x - 5
    4. Factor out yy on the left:
      y(x1)=4x5y(x - 1) = -4x - 5
    5. Divide both sides by x1x - 1:
      y=4x5x1y = \frac{-4x - 5}{x - 1}

So, the inverse is:
g1(x)=4x5x1g^{-1}(x) = \frac{-4x - 5}{x - 1}


2. f(x)=4(x5)+3f(x) = 4(x - 5) + 3

To find the inverse:

  • Replace f(x)f(x) with yy:
    y=4(x5)+3y = 4(x - 5) + 3
  • Swap xx and yy:
    x=4(y5)+3x = 4(y - 5) + 3
  • Solve for yy:
    1. Subtract 3 from both sides:
      x3=4(y5)x - 3 = 4(y - 5)
    2. Divide by 4:
      x34=y5\frac{x - 3}{4} = y - 5
    3. Add 5 to both sides:
      y=x34+5y = \frac{x - 3}{4} + 5

So, the inverse is:
f1(x)=x34+5f^{-1}(x) = \frac{x - 3}{4} + 5


3. f(x)=6x9f(x) = 6\sqrt{x - 9}

To find the inverse:

  • Replace f(x)f(x) with yy:
    y=6x9y = 6\sqrt{x - 9}
  • Swap xx and yy:
    x=6y9x = 6\sqrt{y - 9}
  • Solve for yy:
    1. Divide by 6:
      x6=y9\frac{x}{6} = \sqrt{y - 9}
    2. Square both sides:
      (x6)2=y9\left(\frac{x}{6}\right)^2 = y - 9
    3. Add 9 to both sides:
      y=(x6)2+9y = \left(\frac{x}{6}\right)^2 + 9

So, the inverse is:
f1(x)=(x6)2+9f^{-1}(x) = \left(\frac{x}{6}\right)^2 + 9


4. h(x)=2x1xh(x) = \frac{2x - 1}{x}

To find the inverse:

  • Replace h(x)h(x) with yy:
    y=2x1xy = \frac{2x - 1}{x}
  • Swap xx and yy:
    x=2y1yx = \frac{2y - 1}{y}
  • Solve for yy:
    1. Multiply both sides by yy:
      xy=2y1xy = 2y - 1
    2. Group all terms involving yy on one side:
      xy2y=1xy - 2y = -1
    3. Factor out yy on the left:
      y(x2)=1y(x - 2) = -1
    4. Divide both sides by x2x - 2:
      y=1x2y = \frac{-1}{x - 2}

So, the inverse is:
h1(x)=1x2h^{-1}(x) = \frac{-1}{x - 2}


5. m(x)=x5+1m(x) = x - 5 + 1

This simplifies to:
m(x)=x4m(x) = x - 4

To find the inverse:

  • Replace m(x)m(x) with yy:
    y=x4y = x - 4
  • Swap xx and yy:
    x=y4x = y - 4
  • Solve for yy:
    y=x+4y = x + 4

So, the inverse is:
m1(x)=x+4m^{-1}(x) = x + 4


Would you like more details on any specific step or function?

5 Related Questions:

  1. How do you verify if a function and its inverse are correct?
  2. Can any function have an inverse?
  3. How does the domain and range of a function relate to its inverse?
  4. What are common types of functions that require extra steps to find the inverse?
  5. Why is it important to understand inverses in algebra and calculus?

Tip:

To check if two functions are inverses of each other, compose them (f(f1(x))f(f^{-1}(x))) and see if the result is xx.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Inverse functions
Algebra
Rational functions
Radical functions

Formulas

g(x) = (x - 5) / (x + 4)
f(x) = 4(x - 5) + 3
f(x) = 6√(x - 9)
h(x) = (2x - 1) / x
m(x) = x - 4

Theorems

To find the inverse, swap x and y and solve for y.
For rational functions, multiply through to eliminate fractions.
For radical functions, square both sides to eliminate the square root.

Suitable Grade Level

Grade 10-12