BackCollege Algebra Chapter 3 Review – Step-by-Step Guidance
Study Guide - Smart Notes
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Q1. Determine if the relation is a function. Give the domain and range.
Background
Topic: Relations and Functions
This question tests your understanding of what makes a relation a function, and how to identify the domain and range from a set of ordered pairs.
Key Terms:
Relation: A set of ordered pairs.
Function: A relation where each input (x-value) corresponds to exactly one output (y-value).
Domain: The set of all possible input values (x-values).
Range: The set of all possible output values (y-values).
Step-by-Step Guidance
List all the x-values from the given ordered pairs: .
Check if any x-value is repeated. If each x-value is unique, the relation is a function.
List all the y-values from the ordered pairs to find the range.
Write the domain and range as sets, using curly braces .
Try solving on your own before revealing the answer!
Final Answer:
The relation is a function because no x-value is repeated.
Domain:
Range:
Q2. Evaluate the function at the indicated values.
Background
Topic: Function Evaluation
This question tests your ability to substitute values into a function and simplify the result.
Key Formula:
Step-by-Step Guidance
For part (a), substitute into the function: .
Multiply and then subtract $8$.
For part (b), substitute : .
Multiply and then subtract $8$.
For part (c), substitute into the function: .
Expand and then subtract $8$.
Try solving on your own before revealing the answer!
Final Answer:
(a)
(b)
(c)
Q3. Use the vertical line test to determine if y is a function of x in the graph.
Background
Topic: Functions and Graphs
This question tests your ability to use the vertical line test to determine if a graph represents a function.
Key Concept:
Vertical Line Test: If any vertical line crosses the graph more than once, the graph does not represent a function.
Step-by-Step Guidance
Visualize or draw vertical lines at various x-values on the graph.
Check if any vertical line intersects the graph at more than one point.
If all vertical lines intersect the graph at most once, y is a function of x.
Try solving on your own before revealing the answer!
Final Answer:
y is a function of x if no vertical line crosses the graph more than once.
Q4. Classify the function and find its domain.
Background
Topic: Types of Functions and Domain
This question tests your ability to classify functions and determine their domain.
Key Terms:
Polynomial Function: A function made up of terms with non-negative integer exponents.
Domain: The set of all possible input values (x-values).
Interval Notation: A way to express the domain using intervals.
Step-by-Step Guidance
Identify the type of function by looking at the exponents and terms.
Check for any restrictions on x (such as division by zero or square roots of negative numbers).
Write the domain in interval notation.
Try solving on your own before revealing the answer!
Final Answer:
Polynomial function; domain is
Q5. Find the x-intercept(s) and y-intercept of .
Background
Topic: Intercepts of Rational Functions
This question tests your ability to find where a function crosses the axes.
Key Formulas:
x-intercept: Set and solve for x.
y-intercept: Set and solve for .
Step-by-Step Guidance
For x-intercept(s), set : .
Solve for x where the numerator is zero, but denominator is not zero.
For y-intercept, substitute into : .
Simplify the expression for the y-intercept.
Try solving on your own before revealing the answer!
Final Answer:
x-intercept: ; y-intercept:
Q6. Use the graph to determine the domain and range of the function.
Background
Topic: Domain and Range from Graphs
This question tests your ability to read domain and range from a graph.
Key Terms:
Domain: All x-values for which the function is defined.
Range: All y-values that the function takes.
Interval Notation: Used to express domain and range.
Step-by-Step Guidance
Look at the graph and identify the leftmost and rightmost x-values for the domain.
Identify the lowest and highest y-values for the range.
Write the domain and range in interval notation.
Try solving on your own before revealing the answer!
Final Answer:
Domain: ; Range:
Q7. Determine the intervals where the function is increasing, decreasing, or constant.
Background
Topic: Increasing, Decreasing, and Constant Intervals
This question tests your ability to analyze a graph and describe where the function changes behavior.
Key Terms:
Increasing: Function values go up as x increases.
Decreasing: Function values go down as x increases.
Constant: Function values stay the same as x increases.
Step-by-Step Guidance
Examine the graph and identify intervals where the function rises, falls, or stays flat.
Write each interval in interval notation.
Check for any overlapping or missing intervals.
Try solving on your own before revealing the answer!
Final Answer:
Increasing: ; Decreasing: ; Constant:
Q8. Find the relative minimum and maximum values and their locations.
Background
Topic: Relative Extrema
This question tests your ability to identify relative minimum and maximum points from a graph.
Key Terms:
Relative Minimum: The lowest point in a local region of the graph.
Relative Maximum: The highest point in a local region of the graph.
Step-by-Step Guidance
Look for points on the graph where the function changes from decreasing to increasing (minimum) or increasing to decreasing (maximum).
Identify the x-values where these changes occur.
Find the corresponding y-values for these x-values.
Try solving on your own before revealing the answer!
Final Answer:
Relative minimum at , value $1x = 1
Q9. Determine whether the function is even, odd, or neither.
Background
Topic: Even and Odd Functions
This question tests your ability to classify functions based on symmetry.
Key Concepts:
Even Function: for all x; symmetric about the y-axis.
Odd Function: for all x; symmetric about the origin.
Step-by-Step Guidance
Check the function or graph for y-axis symmetry (even) or origin symmetry (odd).
Test and compare to and .
Try solving on your own before revealing the answer!
Final Answer:
The function is odd.
Q10. Sketch the graph of and identify its properties.
Background
Topic: Graphs of Rational Functions
This question tests your ability to recognize the graph and properties of the reciprocal function.
Key Properties:
Domain: All real numbers except .
Range: All real numbers except .
Odd Function: Symmetric about the origin.
Step-by-Step Guidance
Sketch the graph with two branches, one in each quadrant.
Identify vertical and horizontal asymptotes.
List the domain and range, and check for symmetry.
Try solving on your own before revealing the answer!
Final Answer:
Domain: ; Range: $(-\infty, 0) \cup (0, \infty)$; Odd function
Q11. Sketch the graph of for .
Background
Topic: Graphs with Restricted Domains
This question tests your ability to graph a function with a domain restriction.
Key Concepts:
Restricted Domain: Only graph the function for .
Step-by-Step Guidance
Draw the parabola but only for values where .
Indicate the endpoint at (open or closed circle as appropriate).
Try solving on your own before revealing the answer!
Final Answer:
Graph is the left side of the parabola up to .
Q12. Write the domain and define the function using an inequality for a graph with domain .
Background
Topic: Domain and Function Definition
This question tests your ability to express domain in interval notation and as an inequality.
Key Concepts:
Interval Notation:
Inequality:
Step-by-Step Guidance
Write the domain in interval notation.
Express the domain as an inequality.
Try solving on your own before revealing the answer!
Final Answer:
Domain: ; Inequality:
Q13. Write a function for a graph shifted horizontally and vertically from .
Background
Topic: Transformations of Functions
This question tests your ability to write equations for shifted graphs.
Key Formula:
Step-by-Step Guidance
Identify the horizontal shift and vertical shift from the graph.
Write the function in the form .
Try solving on your own before revealing the answer!
Final Answer:
Q14. Sketch the graph of and determine how points move.
Background
Topic: Function Reflections
This question tests your understanding of reflecting a graph across the y-axis.
Key Concept:
Reflection: reflects the graph across the y-axis.
Step-by-Step Guidance
For each point on the original graph, the reflected point is .
Apply this to each given point to find its new location.
Try solving on your own before revealing the answer!
Final Answer:
Each point moves to .
Q15. Sketch the graph of and describe the transformation.
Background
Topic: Exponential Functions and Transformations
This question tests your ability to recognize vertical stretches and compressions.
Key Formula:
Step-by-Step Guidance
Compare to the basic function to determine the stretch/compression factor.
Sketch the graph with the appropriate vertical transformation.
Try solving on your own before revealing the answer!
Final Answer:
Vertical stretch by a factor of 3.
Q16. Evaluate given , .
Background
Topic: Function Operations
This question tests your ability to multiply two functions and evaluate at a specific value.
Key Formula:
Step-by-Step Guidance
Find by substituting into .
Find by substituting into .
Multiply the two results: .
Try solving on your own before revealing the answer!
Final Answer:
Q17. Use the graphs of and to evaluate expressions.
Background
Topic: Function Operations from Graphs
This question tests your ability to read values from graphs and perform operations.
Key Concepts:
Read and values at specific x-values.
Perform addition, subtraction, multiplication, or division as indicated.
Step-by-Step Guidance
Locate the x-value on the graph and find and .
Apply the operation (add, subtract, multiply, divide).
Try solving on your own before revealing the answer!
Final Answer:
Use the graph to find values and perform the indicated operation.
Q18. For , , find , , , and .
Background
Topic: Function Operations
This question tests your ability to combine functions using addition, subtraction, multiplication, and division.
Key Formulas:
Step-by-Step Guidance
Write each operation using the given functions.
Simplify each expression as much as possible.
Try solving on your own before revealing the answer!
Final Answer:
; ; ;
Q19. Evaluate the composite function at , given .
Background
Topic: Composite Functions
This question tests your ability to evaluate a function composed with itself.
Key Formula:
Step-by-Step Guidance
First, find by substituting into .
Next, substitute the result into again: .
Try solving on your own before revealing the answer!
Final Answer:
Q20. Find for , .
Background
Topic: Composite Functions
This question tests your ability to compose two functions and simplify the result.
Key Formula:
Step-by-Step Guidance
Substitute into : .
Replace with and simplify.
Try solving on your own before revealing the answer!
Final Answer:
Q21. Determine whether the graph of the function is one-to-one.
Background
Topic: One-to-One Functions
This question tests your ability to recognize one-to-one functions from their graphs.
Key Concept:
One-to-One Function: Each y-value corresponds to only one x-value; passes the horizontal line test.
Step-by-Step Guidance
Draw horizontal lines at various y-values on the graph.
If any horizontal line crosses the graph more than once, the function is not one-to-one.
Try solving on your own before revealing the answer!
Final Answer:
The function is not one-to-one if any horizontal line crosses more than once.
Q22. Determine whether and are inverse functions by evaluating and .
Background
Topic: Inverse Functions
This question tests your ability to check if two functions are inverses by composing them.
Key Formula:
If and are inverses, then and .
Step-by-Step Guidance
Write and .
Find by substituting into .
Find by substituting into .
Check if either composition simplifies to .
Try solving on your own before revealing the answer!
Final Answer:
; ; and are not inverse functions.