Math Problem Statement

find the inverse of g(x) and provide both the domain and range of g^-1(x). g(x) = -4 sqrroot of 5-2x then +1

Solution

To find the inverse of the function g(x)=452x+1g(x) = -4\sqrt{5 - 2x} + 1, we need to follow these steps:

Step 1: Replace g(x)g(x) with yy

y=452x+1y = -4\sqrt{5 - 2x} + 1

Step 2: Swap xx and yy to find the inverse

x=452y+1x = -4\sqrt{5 - 2y} + 1

Step 3: Solve for yy (the inverse function)

  1. Subtract 1 from both sides: x1=452yx - 1 = -4\sqrt{5 - 2y}

  2. Divide by -4: x14=52y\frac{x - 1}{-4} = \sqrt{5 - 2y}

  3. Square both sides to eliminate the square root: (x14)2=52y\left(\frac{x - 1}{-4}\right)^2 = 5 - 2y

  4. Simplify the left side: (x1)216=52y\frac{(x - 1)^2}{16} = 5 - 2y

  5. Subtract 5 from both sides: (x1)2165=2y\frac{(x - 1)^2}{16} - 5 = -2y

  6. Multiply by -1: 5(x1)216=2y5 - \frac{(x - 1)^2}{16} = 2y

  7. Divide by 2: y=5(x1)2162y = \frac{5 - \frac{(x - 1)^2}{16}}{2}

Thus, the inverse function g1(x)g^{-1}(x) is: g1(x)=52(x1)232g^{-1}(x) = \frac{5}{2} - \frac{(x - 1)^2}{32}

Step 4: Find the domain and range of g1(x)g^{-1}(x)

  1. Domain of g1(x)g^{-1}(x): The domain of g1(x)g^{-1}(x) is the range of the original function g(x)g(x). Since g(x)=452x+1g(x) = -4\sqrt{5 - 2x} + 1, the square root must be non-negative, meaning 52x05 - 2x \geq 0, or x52x \leq \frac{5}{2}. Therefore, the domain of g(x)g(x) is (,52](-\infty, \frac{5}{2}]. The range of g(x)g(x), and hence the domain of g1(x)g^{-1}(x), is (,1](-\infty, 1].

  2. Range of g1(x)g^{-1}(x): The range of g1(x)g^{-1}(x) is the domain of g(x)g(x), which is (,52](-\infty, \frac{5}{2}].

Final Answer:

  • The inverse function is g1(x)=52(x1)232g^{-1}(x) = \frac{5}{2} - \frac{(x - 1)^2}{32}.
  • Domain of g1(x)g^{-1}(x): (,1](-\infty, 1]
  • Range of g1(x)g^{-1}(x): (,52](-\infty, \frac{5}{2}]

Would you like more details or have any questions?

Here are five related questions:

  1. How do you verify if a function and its inverse are correct?
  2. Can the inverse function have a different range than the original?
  3. What happens if the function includes complex numbers?
  4. How do the transformations in g(x)g(x) affect its inverse?
  5. How does the domain restriction influence the inverse function?

Tip: The domain of a function restricts the allowable values of xx, while the range reflects the possible outputs or values of yy. Always check both when finding inverses.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Radical Equations
Domain and Range

Formulas

Inverse of a function: swap x and y, solve for y
Radical equation: √(expression)
Domain and Range restrictions for square roots

Theorems

Properties of inverse functions
Domain and Range of square root functions

Suitable Grade Level

Grades 10-12