Math Problem Statement

let g(x)=x+2\sqrt{x+2} state the equation for g1^{-1}(x) state the domain of g1^{-1}(x) and graph g(x) and g1^{-1}(x) and solve \displaylinesx25=x+1\placeholder{\displaylines\sqrt{x^2}-5=x+1\\ \placeholder{}}

Solution

Let's go through each part of your request:

1. Inverse of g(x)=x+2g(x) = \sqrt{x+2}

To find the inverse, we swap xx and yy in the equation and solve for yy: g(x)=x+2g(x) = \sqrt{x + 2} Let y=x+2y = \sqrt{x + 2}. To find the inverse: x=y+2x = \sqrt{y + 2} Square both sides: x2=y+2x^2 = y + 2 Now solve for yy: y=x22y = x^2 - 2 Thus, the inverse function is: g1(x)=x22g^{-1}(x) = x^2 - 2

2. Domain of g1(x)g^{-1}(x)

The domain of g1(x)g^{-1}(x) is the range of g(x)g(x). The function g(x)=x+2g(x) = \sqrt{x+2} is defined for x2x \geq -2, and since square roots are non-negative, g(x)0g(x) \geq 0. Therefore, the range of g(x)g(x) is [0,)[0, \infty).

Hence, the domain of g1(x)=x22g^{-1}(x) = x^2 - 2 is [0,)[0, \infty).

3. Graph of g(x)g(x) and g1(x)g^{-1}(x)

We need to graph both g(x)=x+2g(x) = \sqrt{x+2} and g1(x)=x22g^{-1}(x) = x^2 - 2. The graph of an inverse function is a reflection of the original function over the line y=xy = x.

4. Solve the equation

The equation to solve is: x25=x+1\sqrt{x^2} - 5 = x + 1 First, simplify x2\sqrt{x^2}. Since x2=x\sqrt{x^2} = |x|, the equation becomes: x5=x+1|x| - 5 = x + 1

Now, solve this equation for two cases:

Case 1: x0x \geq 0

In this case, x=x|x| = x, so the equation becomes: x5=x+1x - 5 = x + 1 Subtract xx from both sides: 5=1-5 = 1 This is a contradiction, so there are no solutions in this case.

Case 2: x<0x < 0

In this case, x=x|x| = -x, so the equation becomes: x5=x+1-x - 5 = x + 1 Add xx to both sides: 5=2x+1-5 = 2x + 1 Subtract 1 from both sides: 6=2x-6 = 2x Now, divide by 2: x=3x = -3

Thus, the solution to the equation is x=3x = -3.

Would you like me to plot the graphs or explain any part in more detail?


Follow-up Questions

  1. How do we verify the inverse function algebraically?
  2. Why is g1(x)g^{-1}(x) only defined for x0x \geq 0?
  3. Can the solution x=3x = -3 be verified by substitution?
  4. What happens if you try to solve the equation x5=x+1|x| - 5 = x + 1 by squaring both sides directly?
  5. How does the line y=xy = x help in finding inverse function graphs?

Tip:

When solving absolute value equations, always consider both the positive and negative cases separately.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Square Roots
Absolute Value Equations
Function Domain and Range

Formulas

g^(-1)(x) = x^2 - 2
Domain of g^(-1)(x) is [0, ∞)
Absolute value equation: |x| - 5 = x + 1

Theorems

Properties of Inverse Functions
Solving Absolute Value Equations

Suitable Grade Level

Grades 10-12