Math Problem Statement

Given that :x In (3x-2)+5,

i) Find, and state its domain and range.

ii) Hence, show the relationship between the graphs of f and f¹ on a diagram.

(b) The function g and h are defined by g(x)=x+1 and h(x)=ax+3, Given

Solution

To help you with this, I'll break down each part of the question as follows:

(a) Part i: Domain and Range of f(x)=3x2+5f(x) = 3x - 2 + 5

  1. Simplify the expression for f(x)f(x): f(x)=3x2+5=3x+3f(x) = 3x - 2 + 5 = 3x + 3 So, the function simplifies to f(x)=3x+3f(x) = 3x + 3.

  2. Domain of f(x)f(x): Since f(x)=3x+3f(x) = 3x + 3 is a linear function, there are no restrictions on xx. Thus, the domain of f(x)f(x) is: Domain of f(x):xR\text{Domain of } f(x): \quad x \in \mathbb{R}

  3. Range of f(x)f(x): Similarly, because f(x)=3x+3f(x) = 3x + 3 is a linear function, it can take all real values as xx varies over all real numbers. Therefore, the range of f(x)f(x) is also: Range of f(x):f(x)R\text{Range of } f(x): \quad f(x) \in \mathbb{R}

(a) Part ii: Relationship Between ff and f1f^{-1}

The inverse function f1f^{-1} is found by swapping xx and yy in the equation and solving for yy:

  1. Start with y=3x+3y = 3x + 3.

  2. Swap xx and yy to get x=3y+3x = 3y + 3.

  3. Solve for yy: x3=3yy=x33x - 3 = 3y \Rightarrow y = \frac{x - 3}{3} So, the inverse function f1(x)f^{-1}(x) is: f1(x)=x33f^{-1}(x) = \frac{x - 3}{3}

  4. Graphing the Relationship: The graph of f(x)=3x+3f(x) = 3x + 3 and f1(x)=x33f^{-1}(x) = \frac{x - 3}{3} will be reflections of each other over the line y=xy = x. This line acts as the mirror line between a function and its inverse.

(b) Given Functions g(x)=x+1g(x) = x + 1 and h(x)=ax+3h(x) = ax + 3

You mentioned functions g(x)=x+1g(x) = x + 1 and h(x)=ax+3h(x) = ax + 3. Please provide any additional details or questions regarding how these functions are to be used—whether they need composition, comparison, or specific evaluations—so I can continue with the solution.

Let me know if you need a graphical representation or have questions on any part! Here are some further questions to deepen understanding:

  1. How do you find the inverse of a function, and why does swapping xx and yy help?
  2. What general features of linear functions affect their domain and range?
  3. What other types of functions have restricted domains and ranges?
  4. How can you confirm if two functions are inverses by looking at their graphs?
  5. What are other ways to show the relationship between a function and its inverse?

Tip: For any function f(x)f(x), finding the inverse function involves reversing the operations applied to xx, ensuring that the resulting function undoes what f(x)f(x) did.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Functions
Linear Functions
Inverse Functions
Domain and Range
Graph Transformations

Formulas

f(x) = 3x + 3
f⁻¹(x) = (x - 3) / 3

Theorems

Domain and range of linear functions
Inverse function property

Suitable Grade Level

Grades 10-12