From health tips to tech hacks, find it all on IDNLearn.com. Our platform provides accurate, detailed responses to help you navigate any topic with ease.

Question 8 (Essay Worth 10 points)

The functions [tex]f(x) = x^3 + x^2 - 2x + 3[/tex] and [tex]g(x) = \log(x) + 2[/tex] are given.

Part A: What type of functions are [tex]f(x)[/tex] and [tex]g(x)[/tex]? Justify your answer.

Part B: Find the domain and range for [tex]f(x)[/tex] and [tex]g(x)[/tex]. Then compare the domains and compare the ranges of the functions.


Sagot :

To thoroughly address the problem, we will analyze and describe both the nature and characteristics of the given functions [tex]\( f(x) = x^3 + x^2 - 2x + 3 \)[/tex] and [tex]\( g(x) = \log(x) + 2 \)[/tex]. Our analysis will cover the type of each function, and their domain and range. Here's a step-by-step solution:

### Part A: Identify the types of functions

#### Function [tex]\( f(x) = x^3 + x^2 - 2x + 3 \)[/tex]:
1. Type of Function: This function is a polynomial.
- Justification: Polynomial functions are those of the form [tex]\( P(x) = a_n x^n + a_{n-1} x^{n-1} + \dots + a_1 x + a_0 \)[/tex], where [tex]\( n \)[/tex] is a non-negative integer and all coefficients [tex]\( a_0, a_1, \ldots, a_n \)[/tex] are constants.
- For [tex]\( f(x) \)[/tex], the highest power of [tex]\( x \)[/tex] is 3, indicating it is a polynomial of degree 3.

#### Function [tex]\( g(x) = \log(x) + 2 \)[/tex]:
1. Type of Function: This function is a logarithmic function.
- Justification: Logarithmic functions are of the form [tex]\( g(x) = \log_b(x) \)[/tex], where [tex]\( b \)[/tex] is the base of the logarithm (commonly [tex]\( e \)[/tex] for natural logs or 10 for common logs). Since [tex]\( g(x) \)[/tex] includes [tex]\(\log(x)\)[/tex] plus a constant, it falls under the category of a logarithmic function.

### Part B: Determine the domain and range

#### Domain and Range for [tex]\( f(x) = x^3 + x^2 - 2x + 3 \)[/tex]:

1. Domain:
- Description: The domain of a polynomial function is all real numbers.
- Reason: Polynomials are defined for all real [tex]\( x \)[/tex] without any restrictions such as divisions by zero or taking logarithms of non-positive numbers.
- Domain of [tex]\( f(x) \)[/tex]: [tex]\( (-\infty, \infty) \)[/tex]

2. Range:
- Description: The range of a polynomial function of odd degree (where the highest power term has an odd exponent) is all real numbers.
- Reason: Polynomials of odd degree go to [tex]\(\infty\)[/tex] as [tex]\( x \)[/tex] goes to [tex]\(\infty\)[/tex] and to [tex]\(-\infty\)[/tex] as [tex]\( x \)[/tex] goes to [tex]\(-\infty\)[/tex].
- Range of [tex]\( f(x) \)[/tex]: [tex]\( (-\infty, \infty) \)[/tex]

#### Domain and Range for [tex]\( g(x) = \log(x) + 2 \)[/tex]:

1. Domain:
- Description: The domain of logarithmic functions [tex]\( \log(x) \)[/tex] is [tex]\( x > 0 \)[/tex] (positive real numbers).
- Reason: Logarithms are only defined for positive values of [tex]\( x \)[/tex].
- Domain of [tex]\( g(x) \)[/tex]: [tex]\( (0, \infty) \)[/tex]

2. Range:
- Description: The range of a logarithmic function [tex]\( \log(x) \)[/tex] is all real numbers.
- Reason: As [tex]\( x \)[/tex] approaches 0 from the positive side, [tex]\( \log(x) \)[/tex] approaches [tex]\(-\infty\)[/tex], and as [tex]\( x \)[/tex] increases without bound, [tex]\( \log(x) \)[/tex] increases without bound.
- Range of [tex]\( g(x) \)[/tex]: [tex]\( (-\infty, \infty) \)[/tex]

### Comparison of Domains and Ranges

1. Domains:
- [tex]\( f(x) = x^3 + x^2 - 2x + 3 \)[/tex]: Domain is [tex]\( (-\infty, \infty) \)[/tex]
- [tex]\( g(x) = \log(x) + 2 \)[/tex]: Domain is [tex]\( (0, \infty) \)[/tex]
- Comparison: The domain of [tex]\( f(x) \)[/tex] is broader as it includes all real numbers. The domain of [tex]\( g(x) \)[/tex] is restricted to positive real numbers only.

2. Ranges:
- [tex]\( f(x) = x^3 + x^2 - 2x + 3 \)[/tex]: Range is [tex]\( (-\infty, \infty) \)[/tex]
- [tex]\( g(x) = \log(x) + 2 \)[/tex]: Range is [tex]\( (-\infty, \infty) \)[/tex]
- Comparison: Both functions share the same range, which is all real numbers ([tex]\( (-\infty, \infty) \)[/tex]).

Through this detailed analysis, we have identified the types, domains, and ranges of the given functions, along with a comparison of these mathematical properties.
Thank you for using this platform to share and learn. Don't hesitate to keep asking and answering. We value every contribution you make. Your search for answers ends at IDNLearn.com. Thanks for visiting, and we look forward to helping you again soon.