Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.
Вивчайте Algebraic Functions | Functions and Their Properties
Mathematics for Data Science

bookAlgebraic Functions

An algebraic function is any function that can be expressed using basic arithmetic operations and variables. These functions form the backbone of mathematical modeling, allowing you to make predictions and understand patterns.

Types of Algebraic Functions

There are 6 types of functions used in data science, namely:

1. Identity Functions

  • Form: f(x)=xf(x) = x;
  • Use case: representing unchanged data or as a reference in transformations.

2. Constant Functions

  • Form: f(x)=kf(x) = k;
  • Use case: representing fixed quantities like flat fees or baseline values.

3. Linear Functions

  • Form: f(x)=mx+bf(x) = mx + b;
  • Use case: predicting outcomes such as revenue or costs.

4. Polynomial Functions

  • Form: f(x)=anxn+an1xn1+...+a1x+a0f(x) = a_nx^n + a_{n - 1}x^{n - 1} + ... + a_1x + a_0;
  • Use case: regression models, curve fitting, and describing real-world phenomena like parabolic motion.

5. Rational Functions

  • Form:
f(x)=p(x)q(x);f(x) = \frac{p(x)}{q(x)};
  • Use case: modeling constrained systems, such as rates of change or resource usage.

Behavior of Functions in Python

Now that you've seen these functions in action, here's a summary of their behavior:

1. Identity Function

Equation: f(x)=xf(x) = x

Behavior:

  • Passes through the origin (0,0)(0,0);
  • A straight line with a slope: m=1m = 1;
  • Every input maps to itself;
  • No maximum or minimum;
  • Domain: (,)(-\infty, \infty);
  • Range: (,)(-\infty, \infty).

2. Constant Function

Equation: f(x)=cf(x) = c

Behavior:

  • A horizontal line at: y=cy = c;
  • The function output remains constant regardless of input;
  • Slope: m=0m = 0;
  • No maximum or minimum;
  • Domain: (,)(-\infty, \infty);
  • Range: {c}\{c\}.

3. Linear Function

Equation: f(x)=mx+bf(x) = mx + b

Behavior:

  • A straight line with slope: mm;
  • If m>0m > 0 the function is increasing; if m<0m < 0 the function is decreasing.
  • X-intercept:
x=bm;x = -\frac{b}{m};
  • Y-intercept: y=by = b;
  • No maximum or minimum;
  • Domain: (,)(-\infty, \infty);
  • Range: (,)(-\infty, \infty).

4. Polynomial Function (Quadratic Example)

Equation: f(x)=ax2+bx+cf(x) = ax^2 + bx + c

Behavior:

  • Parabolic curve (U-shaped if a>0a > 0; inverted U if a<0a < 0);
  • Has a vertex at:
x=b2a;x = -\frac{b}{2a};
  • X-intercepts (roots) found using the quadratic formula:
x=b±b24ac2a;x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a};
  • Y-intercept: f(0)=cf(0) = c;
  • Domain: (,)(-\infty, \infty);
  • Range:
    • If a>0a > 0 then [y vertex;)[y_{\ vertex}; \infty);
    • If a<0a < 0 then (;y vertex](-\infty; y_{\ vertex}].

5. Rational Function

Equation:

f(x)=1x1;f(x) = \frac{1}{x - 1};

Behavior:

  • Vertical asymptote at: x1x-1;
  • Horizontal asymptote at: y=0y = 0;
  • Undefined at x=1x = 1;
  • Rapidly decreases and increases near the vertical asymptote;
  • Domain: (,1)(1,),(,0)(0,)(-\infty, 1) \cup (1, \infty), (-\infty, 0) \cup (0, \infty).

1. Write a Python function that represents the following polynomial function and evaluate it at x=4x = 4:

f(x)=5x32x2+7x3f(x) = 5x^3 - 2x^2 + 7x - 3

2. What is the output of f(x)=2x+3f(x) = 2x + 3 when x=4x = 4?

question mark

Write a Python function that represents the following polynomial function and evaluate it at x=4x = 4:

f(x)=5x32x2+7x3f(x) = 5x^3 - 2x^2 + 7x - 3

Select the correct answer

question mark

What is the output of f(x)=2x+3f(x) = 2x + 3 when x=4x = 4?

Select the correct answer

Все було зрозуміло?

Як ми можемо покращити це?

Дякуємо за ваш відгук!

Секція 1. Розділ 4

Запитати АІ

expand

Запитати АІ

ChatGPT

Запитайте про що завгодно або спробуйте одне із запропонованих запитань, щоб почати наш чат

Awesome!

Completion rate improved to 1.89

bookAlgebraic Functions

Свайпніть щоб показати меню

An algebraic function is any function that can be expressed using basic arithmetic operations and variables. These functions form the backbone of mathematical modeling, allowing you to make predictions and understand patterns.

Types of Algebraic Functions

There are 6 types of functions used in data science, namely:

1. Identity Functions

  • Form: f(x)=xf(x) = x;
  • Use case: representing unchanged data or as a reference in transformations.

2. Constant Functions

  • Form: f(x)=kf(x) = k;
  • Use case: representing fixed quantities like flat fees or baseline values.

3. Linear Functions

  • Form: f(x)=mx+bf(x) = mx + b;
  • Use case: predicting outcomes such as revenue or costs.

4. Polynomial Functions

  • Form: f(x)=anxn+an1xn1+...+a1x+a0f(x) = a_nx^n + a_{n - 1}x^{n - 1} + ... + a_1x + a_0;
  • Use case: regression models, curve fitting, and describing real-world phenomena like parabolic motion.

5. Rational Functions

  • Form:
f(x)=p(x)q(x);f(x) = \frac{p(x)}{q(x)};
  • Use case: modeling constrained systems, such as rates of change or resource usage.

Behavior of Functions in Python

Now that you've seen these functions in action, here's a summary of their behavior:

1. Identity Function

Equation: f(x)=xf(x) = x

Behavior:

  • Passes through the origin (0,0)(0,0);
  • A straight line with a slope: m=1m = 1;
  • Every input maps to itself;
  • No maximum or minimum;
  • Domain: (,)(-\infty, \infty);
  • Range: (,)(-\infty, \infty).

2. Constant Function

Equation: f(x)=cf(x) = c

Behavior:

  • A horizontal line at: y=cy = c;
  • The function output remains constant regardless of input;
  • Slope: m=0m = 0;
  • No maximum or minimum;
  • Domain: (,)(-\infty, \infty);
  • Range: {c}\{c\}.

3. Linear Function

Equation: f(x)=mx+bf(x) = mx + b

Behavior:

  • A straight line with slope: mm;
  • If m>0m > 0 the function is increasing; if m<0m < 0 the function is decreasing.
  • X-intercept:
x=bm;x = -\frac{b}{m};
  • Y-intercept: y=by = b;
  • No maximum or minimum;
  • Domain: (,)(-\infty, \infty);
  • Range: (,)(-\infty, \infty).

4. Polynomial Function (Quadratic Example)

Equation: f(x)=ax2+bx+cf(x) = ax^2 + bx + c

Behavior:

  • Parabolic curve (U-shaped if a>0a > 0; inverted U if a<0a < 0);
  • Has a vertex at:
x=b2a;x = -\frac{b}{2a};
  • X-intercepts (roots) found using the quadratic formula:
x=b±b24ac2a;x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a};
  • Y-intercept: f(0)=cf(0) = c;
  • Domain: (,)(-\infty, \infty);
  • Range:
    • If a>0a > 0 then [y vertex;)[y_{\ vertex}; \infty);
    • If a<0a < 0 then (;y vertex](-\infty; y_{\ vertex}].

5. Rational Function

Equation:

f(x)=1x1;f(x) = \frac{1}{x - 1};

Behavior:

  • Vertical asymptote at: x1x-1;
  • Horizontal asymptote at: y=0y = 0;
  • Undefined at x=1x = 1;
  • Rapidly decreases and increases near the vertical asymptote;
  • Domain: (,1)(1,),(,0)(0,)(-\infty, 1) \cup (1, \infty), (-\infty, 0) \cup (0, \infty).

1. Write a Python function that represents the following polynomial function and evaluate it at x=4x = 4:

f(x)=5x32x2+7x3f(x) = 5x^3 - 2x^2 + 7x - 3

2. What is the output of f(x)=2x+3f(x) = 2x + 3 when x=4x = 4?

question mark

Write a Python function that represents the following polynomial function and evaluate it at x=4x = 4:

f(x)=5x32x2+7x3f(x) = 5x^3 - 2x^2 + 7x - 3

Select the correct answer

question mark

What is the output of f(x)=2x+3f(x) = 2x + 3 when x=4x = 4?

Select the correct answer

Все було зрозуміло?

Як ми можемо покращити це?

Дякуємо за ваш відгук!

Секція 1. Розділ 4
some-alt