How to find domain and range of a function algebraically

1. Finding the domain of a function algebraically involves solving for the values of x that make the function undefined.

A function's domain is the set of all input values for which the function produces a result. The domain of a function can be determined algebraically by solving for the values of x that make the function undefined.

2. To do this, set the function equal to y and solve for x.

A domain is the set of all possible input values for a function. To find the domain of a function, set the function equal to y and solve for x. This will give you the set of all x-values for which the function produces a real y-value.

3. Any values of x that make the function undefined will be excluded from the domain.

A function's domain is the set of all input values for which the function produces a result. Any values of x that make the function undefined will be excluded from the domain. For example, the domain of the function f(x) = 1/x will exclude any values of x that result in a division by zero.

4. In some cases, it may be necessary to use the Quadratic Formula to solve for x.

A domain is the set of all possible input values for a function. In some cases, it may be necessary to use the Quadratic Formula to solve for x. The Quadratic Formula is a mathematical formula used to solve for the roots of a quadratic equation.

5. The domain of a function can also be graphed to visualize where the function is defined.

The domain of a function is the set of all input values for which the function produces a result. The domain of a function can also be graphed to visualize where the function is defined. The graph of the domain is a visual representation of the function's inputs and outputs.

$\begingroup$

I've been having trouble when trying to find the domain/range of functions algebraically. Here is an example:

$P(x)=\frac{1}{3+\sqrt{x+1}}$

Finding the domain:

$x+1\ge0$

$x\ge-1$

Therefore, $x \in [-1,+\infty)$

Finding the range: Let $y=P(x)=\frac{1}{3+\sqrt{x+1}}$ From isolating x we find:

$x=(\frac{1}{y} -3)^2-1$

Therefore:

$(\frac{1}{y} -3)^2-1\ge-1$

$(\frac{1}{y} -3)^2\ge0$

$\frac{1}{y} -3\ge0$ or $\frac{1}{y} -3\le0$

$y\le \frac{1}{3}$ or $y\ge \frac{1}{3}$

This doesn't make any sense! Intuitively I can see that when $x=-1$ then $f(x)=\frac{1}{3}$ and as x approaches $+\infty$ then $f(x)$ approaches zero (without ever reaching it). How do I find this solution algebraically? What are the "rules" for working with inequalities w/ exponents and radicals (both positive and negative)? How do I find the range for other functions such as $g(x)=3+\sqrt{16-(x-3)^2}$ and $h(x)=\frac{12x-9}{6-9x}$ algebraically? A thorough explanation would be appreciated (also, feel free to point out errors in my work- there are obviously many).

NSA

1,2217 silver badges24 bronze badges

asked Jun 15, 2016 at 15:20

$\endgroup$

2

$\begingroup$

You are making things more difficult than necessary in your effort to find the range. It is not really necessary to yield an inverse (as you seem to do). You could do it in simple steps:

  • range of $\sqrt{1+x}$ is $[0,\infty)$
  • range of $3+\sqrt{1+x}$ is $[3,\infty)$
  • range of $\frac{1}{3+\sqrt{1+x}}$ is $(0,\frac13]$

answered Jun 15, 2016 at 15:40

See More....

How to find the domain of a function calculator?

Part 1 Part 1 of 3: Finding the Domain of a Function

  1. Determine the type of function you’re working with. The domain of the function is all of the x-values (horizontal axis) that will give you a valid y-value output.
  2. Write the domain with proper notation. Writing the domain of a function involves the use of both brackets [,] and parentheses (,).
  3. Draw a graph of the quadratic equation. ...

More items...

How do you algebraically find the domain of a function?

How To Find Domain Of Functions Algebraically.
Finding the domain of a function algebraically involves solving for the values of x that make the function undefined. ... .
To do this, set the function equal to y and solve for x. ... .
Any values of x that make the function undefined will be excluded from the domain..

How do you find the range of an algebraic expression?

To determine the range of this data set, take the largest number and subtract it with the smallest number.

How do you find the domain and range of a function without a graph?

HOW TO FIND DOMAIN AND RANGE OF A FUNCTION WITHOUT GRAPHING.
Step 1 : Put y = f(x).
Step 2 : Solve the equation y = f(x) for x in terms of y. ... .
Step 3 : Find the values of y for which the values of x, obtained from x = g(y) are real and its domain of f..
Step 4 :.

How do we find the range of a function?

How to Find the Range of a Function. Consider a function y = f(x). The spread of all the y values from minimum to maximum is the range of the function. In the given expression of y, substitute all the values of x to check whether it is positive, negative or equal to other values.

Toplist

Latest post

TAGs