뒤로Business Calculus Chapter 3 Skills Review Guidance
스터디 가이드 - 스마트 노트
자료에 맞춘 맞춤형 노트, 핵심 정의, 예시, 맥락을 확장해 제공합니다.
Q1. Find an equation of the line that contains the given pair of points: (−9, 3) and (−7, −5). Write your answer in slope-intercept form.
Background
Topic: Linear Equations
This question tests your ability to find the equation of a line given two points, and to express it in slope-intercept form ().
Key Terms and Formulas:
Slope formula:
Slope-intercept form:
Step-by-Step Guidance
Label your points: Let and .
Calculate the slope using the formula: .
Substitute the values for into the slope formula and simplify.
Use the point-slope form with one of the points to set up the equation.
Rearrange the equation into slope-intercept form (), but stop before calculating the final value of .
Try solving on your own before revealing the answer!
Final Answer:
Using the slope formula, . Plugging into with one point, you solve for and get .
Q2. Find the slope-intercept equation of the line with slope 8 and y-intercept (0, 4).
Background
Topic: Linear Equations
This question checks your understanding of how to write the equation of a line when given the slope and y-intercept.
Key Terms and Formulas:
Slope-intercept form:
is the slope, is the y-intercept
Step-by-Step Guidance
Recall the slope-intercept form: .
Identify the given values: , .
Substitute these values into the formula to write the equation.
Try solving on your own before revealing the answer!
Final Answer:
Plugging in and gives .
Q3. Graph the equation by plotting points:
Background
Topic: Graphing Linear Equations
This question tests your ability to graph a linear equation by plotting points and understanding the slope and y-intercept.
Key Terms and Formulas:
Slope-intercept form:
Slope (): rise over run
Y-intercept (): where the line crosses the y-axis
Step-by-Step Guidance
Identify the slope () and y-intercept ().
Plot the y-intercept point on the graph.
From the y-intercept, use the slope to find another point: rise 4 units, run 1 unit to the right.
Plot at least one more point using the slope, then draw a straight line through the points.
Try solving on your own before revealing the answer!
Final Answer: The line passes through (0, -3) and (1, 1), with slope 4.
Plot the y-intercept at (0, -3), then from there, move up 4 and right 1 to (1, 1), and draw the line.
Q4. Graph the equation by plotting points:
Background
Topic: Graphing Linear Equations
This question checks your ability to graph a line with a fractional slope and a y-intercept.
Key Terms and Formulas:
Slope-intercept form:
Slope (): means rise 1, run 2
Y-intercept (): 2
Step-by-Step Guidance
Identify the slope () and y-intercept ().
Plot the y-intercept at .
From , use the slope: up 1, right 2 to plot another point.
Draw the line through the points.
Try solving on your own before revealing the answer!
Final Answer: The line passes through (0, 2) and (2, 3).
Plot (0, 2), then up 1 and right 2 to (2, 3), and draw the line.
Q5. Simplify by removing factors of 1:
Background
Topic: Simplifying Rational Expressions
This question tests your ability to factor polynomials and reduce rational expressions to lowest terms.
Key Terms and Formulas:
Difference of squares:
Perfect square trinomial:
Reducing rational expressions: Cancel common factors in numerator and denominator
Step-by-Step Guidance
Factor the numerator: as a difference of squares.
Factor the denominator: as a perfect square trinomial.
Write the expression with the factored forms.
Identify and cancel any common factors.
Try solving on your own before revealing the answer!
Final Answer:
Factoring gives , so cancel one factor.
Q6. Reduce the rational expression to lowest terms:
Background
Topic: Simplifying Rational Expressions
This question tests your ability to factor quadratic expressions and reduce rational expressions.
Key Terms and Formulas:
Factoring quadratics:
Reducing rational expressions: Cancel common factors
Step-by-Step Guidance
Factor the numerator .
Factor the denominator .
Write the expression with the factored forms.
Identify and cancel any common factors.
Try solving on your own before revealing the answer!
Final Answer:
Factoring numerator: . Denominator: . Cancel and reduce.
Q7. Use the graph of and transformations to sketch . Determine the domain, range, y-intercept, and equation of the horizontal asymptote.
Background
Topic: Exponential Functions and Transformations
This question tests your understanding of how to graph exponential functions and identify their key features.
Key Terms and Formulas:
Exponential function:
Domain: All possible values
Range: All possible values
Horizontal asymptote:
Step-by-Step Guidance
Recognize that is a horizontal shift of to the right by 6 units.
Recall that the domain of exponential functions is all real numbers.
The range is all positive real numbers (since for all ).
The horizontal asymptote is (no vertical shift).
To find the y-intercept, set and compute , but stop before calculating the final value.
Try solving on your own before revealing the answer!
Final Answer:
Domain:
Range:
y-intercept:
Horizontal asymptote:
The function is shifted right by 6 units, but the domain and range remain the same as the parent function.
Q8. Use the graph of and transformations to sketch . Determine the domain, range, y-intercept, and equation of the horizontal asymptote.
Background
Topic: Exponential Functions and Transformations
This question tests your ability to apply transformations to exponential functions and identify their key features.
Key Terms and Formulas:
Reciprocal of exponential:
Vertical shift: moves the graph up by 6 units
Horizontal asymptote:
Step-by-Step Guidance
Rewrite as to see the reflection and shift.
Domain is all real numbers.
Range is since is always positive.
Horizontal asymptote is .
To find the y-intercept, set and compute , but stop before calculating the final value.
Try solving on your own before revealing the answer!
Final Answer:
Domain:
Range:
y-intercept:
Horizontal asymptote:
The function is a reflection and vertical shift of the parent exponential function.
Q9. Rewrite as a sum or difference of multiples of logarithms:
Background
Topic: Properties of Logarithms
This question tests your ability to expand logarithmic expressions using the product and power rules.
Key Terms and Formulas:
Product rule:
Power rule:
Step-by-Step Guidance
Apply the product rule to separate , , and .
Apply the power rule to and .
Write the expanded expression as a sum of logarithms.
Try solving on your own before revealing the answer!
Final Answer:
Each exponent becomes a coefficient in front of the corresponding logarithm.
Q10. Express as a sum and/or difference of logarithms.
Background
Topic: Properties of Logarithms
This question tests your ability to expand a logarithm of a quotient and product using logarithm rules.
Key Terms and Formulas:
Quotient rule:
Product rule:
Power rule:
Step-by-Step Guidance
Apply the quotient rule to separate numerator and denominator.
Apply the product rule to the numerator and denominator .
Apply the power rule to and .
Write the expanded expression as a sum and/or difference of logarithms.
Try solving on your own before revealing the answer!
Final Answer:
Each term is expanded using the appropriate logarithm rule.
Q11. Graph the function
Background
Topic: Graphing Linear Functions
This question tests your ability to graph a linear function using its slope and y-intercept.
Key Terms and Formulas:
Slope-intercept form:
Slope (): 6
Y-intercept (): -9
Step-by-Step Guidance
Identify the slope and y-intercept from the equation.
Plot the y-intercept at .
From , use the slope: up 6, right 1 to plot another point.
Draw the line through the points.
Try solving on your own before revealing the answer!
Final Answer: The line passes through (0, -9) and (1, -3).
Plot (0, -9), then up 6 and right 1 to (1, -3), and draw the line.
Q12. Graph the function
Background
Topic: Graphing Linear Functions
This question tests your ability to graph a linear function with a fractional coefficient.
Key Terms and Formulas:
Rewrite as
Slope:
Y-intercept:
Step-by-Step Guidance
Rewrite the function in slope-intercept form.
Identify the slope and y-intercept.
Plot the y-intercept at .
From the y-intercept, use the slope to plot another point.
Draw the line through the points.
Try solving on your own before revealing the answer!
Final Answer: The line passes through (0, -3.5) and (2, -2.5).
Plot (0, -3.5), then up 1 and right 2 to (2, -2.5), and draw the line.
Q13. Graph and state the domain:
Background
Topic: Rational Functions
This question tests your understanding of the graph and domain of a rational function.
Key Terms and Formulas:
Rational function:
Domain: All real numbers except where the denominator is zero
Step-by-Step Guidance
Identify values of that make the denominator zero.
State the domain in interval notation, excluding .
Recognize the graph is a hyperbola with asymptotes at and .
Try solving on your own before revealing the answer!
Final Answer: Domain is
The function is undefined at , so exclude that value from the domain.
Q14. Graph:
Background
Topic: Rational Functions
This question tests your ability to graph a rational function with a negative numerator.
Key Terms and Formulas:
Rational function:
Asymptotes: (vertical), (horizontal)
Step-by-Step Guidance
Recognize the function is undefined at .
For , is negative; for , is positive.
Sketch the hyperbola in the appropriate quadrants.
Try solving on your own before revealing the answer!
Final Answer: The graph is a hyperbola in quadrants II and IV, with asymptotes at and .
For positive , is negative; for negative , is positive.