All Algebra II Resources
Example Questions
Example Question #93 : Domain And Range
Determine the range of:
Rewrite this in form. The equation given is a parabola.
The negative ten coefficient tells us that the parabola will open downward.
The negative three indicates that the y-intercept is at .
Since the curve opens downward, there will be a maximum at the vertex, which is at , since the vertex is zero as there is no coefficient for .
This means the range will start at negative infinity, and ends at negative three.
The answer is:
Example Question #94 : Domain And Range
Determine the range of:
The equation in slope-intercept form, , is:
This is a horizontal line, and the y-value will be fixed at this value, which means the range will not change. Be careful not to misinterpret or three as the slope!
The answer is:
Example Question #95 : Domain And Range
What is the domain of the function f(x) where
None of the other answers
Recall that the domain of the function f(x) is the set of all x where f(x) is defined. Also, recall that two of the most common ways that a function can be undefined are division by zero and a negative inside of a square root. So, we need to ensure that are domain excludes all x values for which those things can occur.
The portion of our equation is of no concern, as the domain of is all real numbers - that is to say, we can plug any real number into and it will be defined. However, the of our equation is cause for concern. We need to avoid two issues here - division by zero, and having a negative in the square root. We know that the only x value that would result in a zero in our denominator is zero, as the square root of zero is zero. That is, if we substitute zero for x, we will have in our denominator, which evaluates to , leaving a zero in our denominator, leaving us with an undefined function. So, we need to exclude zero from our domain. Secondly, we need to exclude all number below zero from our domain as well, as x values below zero would result in a negative inside of a square root, which would result in an undefined function.
So, summarizing, we need to exclude all numbers below zero as well as zero itself from our domain, resulting in a final answer of:
Example Question #96 : Domain And Range
Find the domain of the function q(x) where
Recall that the domain of the function q(x) is the set of all x values that result in the function q(x) being defined. In this case, what we need to think about is avoiding a negative number inside of the radical (or square root symbol), which would result in an undefined function. What this means is that we need to all the x values for which the expression inside of the radical is greater than or equal to zero. In mathematical terms, we need to solve for x in the inequality:
Thus, we will have a positive or zero value inside of the radical only when x is less than or equal to -4 and greater than or equal to 4. If we look at the expression inside the radical, this makes sense - for all x values between -4 and 4, will evaluate to a number less than 16, which will result in a negative inside of the radical and therefore an undefined function. For x values less than or equal to -4 and greater than or equal to 4, will evaluate to a number greater than or equal to 16, which will result in a positive inside of the radical and therefore a defined function. Written in interval notation, this domain looks like:
Example Question #97 : Domain And Range
What is the range of the function?
The range of the parent function is all real numbers. The coefficient of the x cubed term will widen the curve, and flip the graph since it is a negative value. The coefficient will not affect the range.
The negative ten at the end will only shift the graph downward 10 units and also will not affect the range of the function.
This means that the range includes all real numbers.
The answer is:
Example Question #98 : Domain And Range
What is the range of the following function in interval notation?
The equation given is in the form of .
Since the value of , the location of the vertex will be at .
Substitute in order to determine the min or max of this curve. Since the coefficient is positive, the parabola will open upward, and will have a minimum. The coefficient will not affect the range.
The minimum point is .
The range is including all y-values that are existent on this graph.
The answer is:
Example Question #99 : Domain And Range
A function is defined on the domain according to the following table:
Define a function .
Which of the following values is not in the range of the function ?
This is the composition of two functions. By definition, . To find the range of , we need to find the values of this function for each value in the domain of . Since , this is equivalent to evaluating for each value in the range of , as follows:
Range value: 3
Range value: 5
Range value: 8
Range value: 13
Range value: 21
The range of on the set of range values of - and consequently, the range of - is the set . Of the choices given, only 1 is not in this set.
Example Question #91 : Domain And Range
Find the domain of the rational function,
The domain of a function is the set of all values of the independent variable, , over which the function is defined. The first step is usually to find where the function is undefined. For a rational function this is always going to consist of points where the denominator is zero.
Find the roots of the denominator:
(1)
This is not one we can easily factor. Therefore, we should use the quadratic formula.
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Recall that for a quadratic of the form the general form of the solution is,
(2)
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The solution to equation (1) is,
(3)
The two roots are:
Now that we have the roots for the denominator we can construct the domain using interval notation. Use open parenthesis to exclude the two roots themselves from the domain. Also think of how the roots will split up the number line into three regions.
The total domain of our function in interval notation is:
Example Question #21 : Range And Domain
Find the domain and range of the function . Express the domain and range in interval notation.
Domain
Range
(all real numbers)
Domain
Range
Domain
Range
Domain
(all real numbers)
Range
Domain
Range
Domain
Range
Finding the Domain
The domain of a function is defined as the set of all valid input values of overwhich the function is defined. The simple rule of thumb for rational functions is that all real numbers will work except for those in which denominator is zero since division by zero is not allowed.
Set the denominator to zero and solve for ,
The function is therefore defined everywhere except at . Therefore the domain expressed in interval notation is,
Note that the open parentheses indicate that is not in the domain, but may become arbitrarily close to .
Finding the Range
The range of a function is defined as the set of all outputs spanning the domain. Finding the range can be achieved by finding the domain of the inverse function. First solve for to obtain the inverse function,
Multiply both sides by ,
Distribute ,
Move all terms with to one side of the equation,
Factor and solve for
The inverse function is therefore,
Find the domain of the inverse function,
The range of is the domain of , which is:
If you look at the plots for the function (in blue) and (in red and labeled as in the figure) you can see the asymptotic behavior of as approaches and of as approaches .
Example Question #1 : Function Notation
Let and . What is ?
THe notation is a composite function, which means we put the inside function g(x) into the outside function f(x). Essentially, we look at the original expression for f(x) and replace each x with the value of g(x).
The original expression for f(x) is . We will take each x and substitute in the value of g(x), which is 2x-1.
We will now distribute the -2 to the 2x - 1.
We must FOIL the term, because .
Now we collect like terms. Combine the terms with just an x.
Combine constants.
The answer is .