# Graphs of Common Functions

## The Importance of Understanding Various Function Graphs in Mathematics

In the world of mathematics, graphs of common functions play a significant role in visualizing complex mathematical concepts. A function is a crucial mathematical concept that represents the relationship between an input value (x) and an output value (y). These graphs illustrate the relationship between independent and dependent variables.

There are different types of function graphs that are frequently used in mathematics. Let's take a closer look at each of them:

**Constant Function:**This type of function, f(x) = c, has a straight line graph parallel to the x-axis, with the point y = c intersecting the y-axis.**Linear (Identity) Function:**The graph of a linear function is also a straight line, but with a varying slope depending on its value.**Quadratic Function:**When graphed, this function has a parabolic shape.**Cubic Function:**Cubic graphs are smooth continuous lines with maximum or minimum points in the middle and either positive or negative infinity at both ends.**Square Root Function:**The graph of a square root function has a distinct shape due to the restricted domain (x ≥ 0), where only positive values are used.**Cube Root Function:**Unlike the square root function, this graph has no restricted domain, allowing for both negative and positive values of x.**Modulus or Absolute Value Function:**The characteristic V-shape of this graph is similar to f(x) = x, but with negative y values reflected on the x-axis.**Reciprocal Function:**This graph has asymptotes at x = 0 and y = 0.**Reciprocal Squared Function:**With x^{2}in the denominator, the graph of this function differs from the reciprocal function, having only positive y values.**Exponential Function:**The graph of an exponential function has a horizontal asymptote at y = 0 and intersects the y-axis at (0, 1), before increasing rapidly.**Logarithmic Function:**The inverse of the exponential function, its graph is a reflection over the line y = x, with a vertical asymptote at x = 0 and crossing the x-axis at (1, 0).**Trigonometric Functions:**These periodic functions (sine, cosine, tangent) have a unique shape due to their periodicity, meaning they repeat themselves at regular intervals.

Now, let's delve into the details of the graphs of each trigonometric function:

**Sine Function:**With a maximum value of 1, a minimum value of -1, and repeating every 2π radians or 360°, the graph of sine crosses the y-axis at the origin (0, 0).**Cosine Function:**Similar to the sine graph, the cosine graph also has a maximum value of 1, a minimum value of -1, and repeats every 2π radians or 360°.**Tangent Function:**The tangent graph has no maximum or minimum points and repeats itself every π, with vertical asymptotes at π/2, π, 3π/2, etc.

## Improve Your Maths Skills by Understanding Function Graphs

Proficiency in Maths requires a strong understanding of function graphs. By familiarizing yourself with the various types of function graphs, you can easily identify the type of function a graph represents and solve complex problems with ease. Keep practicing to enhance your skills further!

## Understanding and Identifying Common Function Graphs

When trying to determine the common function of a graph, it is useful to become acquainted with the shapes and features of different function graphs. By paying attention to these distinct characteristics and their corresponding formulas, such as the shape of the curve, you can easily identify the type of function represented by a graph. Memorizing a list of commonly used function graphs can also aid in this skill, particularly when solving specific problems.

### Identifying Functions on a Graph

If presented with a graph and asked to determine if it represents a function, the following tests can be utilized:

**Vertical Line Test:**Draw vertical lines intersecting the graph. If any of these lines intersect the graph more than once, then the graph is not a function (x has multiple outputs).**Horizontal Line Test:**Draw a horizontal line and observe if it intersects the graph more than once. If this is the case, the function is not one-to-one.

Example of the vertical line test, Marilú García De Taylor - StudySmarter Originals

This graph does not represent a function because the vertical line intersects two points on the graph.

Example of the horizontal line test, Marilú García De Taylor - StudySmarter Originals

This graph is a function since it passes the vertical line test. However, it is not one-to-one as the horizontal line intersects the graph twice.

## The Key Concepts of Common Function Graphs

- A function is a mathematical construct that takes x values and produces y values in a one-to-one or many-to-one correspondence.
- Common function graphs are visual representations of frequently used functions in mathematics.
- Knowing the shapes, features, and formulas of different function graphs can aid in identifying the type of function a graph represents.
- The vertical line test is utilized to confirm if a graph represents a function.
- The horizontal line test is used to determine if a function is one-to-one.

## Examples of Function Graphs

There are many different types of function graphs, such as:

- Constant: f(x) = c, where c is a constant
- Linear (Identity): f(x) = x
- Quadratic: f(x) = x²
- Cubic: f(x) = x³
- Square Root: f(x) = √x
- Cube Root: f(x) = ∛x
- Modulus or Absolute Value: f(x) = |x|
- Reciprocal: f(x) = 1/x
- Reciprocal Squared: f(x) = 1/x²
- Exponential: f(x) = e^x
- Logarithmic: f(x) = ln(x)
- Trigonometric Functions: f(x) = sin(x), f(x) = cos(x), and f(x) = tan(x)

## To Sum it Up

In summary, common functions are visual representations of frequently used functions in mathematics. By understanding the shapes and features of different function graphs, you can quickly identify the type of function a graph represents. Use the vertical and horizontal line tests to confirm if a graph is a function and if it is one-to-one. Continue to practice and familiarize yourself with the various types of function graphs to improve your proficiency in this area.