Which graph represents a function?
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A.
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B.
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C.
Correct Answer & Rationale
Correct Answer: B
To determine which graph represents a function, we apply the Vertical Line Test. This test states that if a vertical line intersects the graph at more than one point, the graph does not represent a function. Option A fails this test, as a vertical line can intersect the graph at multiple points, indicating it is not a function. Option C also does not satisfy the criteria, showing multiple intersections with vertical lines. In contrast, Option B passes the Vertical Line Test, as any vertical line drawn will intersect the graph at only one point, confirming it represents a function.
To determine which graph represents a function, we apply the Vertical Line Test. This test states that if a vertical line intersects the graph at more than one point, the graph does not represent a function. Option A fails this test, as a vertical line can intersect the graph at multiple points, indicating it is not a function. Option C also does not satisfy the criteria, showing multiple intersections with vertical lines. In contrast, Option B passes the Vertical Line Test, as any vertical line drawn will intersect the graph at only one point, confirming it represents a function.
Other Related Questions
Daniel is planning to buy his first house. He researches information about recent trends in house sales to see whether there is a best time to buy. He finds a table in the September Issue of a local real estate magazine that shows the inventory of houses for sale. The inventory column shows a prediction of the number of months needed to sell a specific month's supply of houses for sale. The table also shows the median sales price for houses each month.
Daniel wonders whether housing prices are more likely to increase or decrease in any special month. If he randomly selects a month other than January from the table, what is the price as a fraction, that the median sales price in that month was an increase over the previous month?
Correct Answer & Rationale
Correct Answer: 4\7
To determine the fraction of months where the median sales price increased over the previous month, one must analyze the data presented in the table. The correct answer, 4/7, indicates that out of the seven months considered (excluding January), there were four months where prices rose compared to the month prior. Other options, such as 3/7 or 5/7, misrepresent the data by either underestimating or overestimating the actual increases. A fraction of 3/7 would imply that only three months saw an increase, which contradicts the evidence. Similarly, 5/7 would suggest an unrealistic majority of months experienced price hikes, not aligning with the data. Thus, 4/7 accurately reflects the observed trends in the provided data.
To determine the fraction of months where the median sales price increased over the previous month, one must analyze the data presented in the table. The correct answer, 4/7, indicates that out of the seven months considered (excluding January), there were four months where prices rose compared to the month prior. Other options, such as 3/7 or 5/7, misrepresent the data by either underestimating or overestimating the actual increases. A fraction of 3/7 would imply that only three months saw an increase, which contradicts the evidence. Similarly, 5/7 would suggest an unrealistic majority of months experienced price hikes, not aligning with the data. Thus, 4/7 accurately reflects the observed trends in the provided data.
Read the phrase below.
the quotient of three less than a number and six more than four times a number
Which expression is equivalent to this phrase?
- A. (3-x)/(4x + 6)
- B. (x - 3)(4x + 6)
- C. (x-3)/(4x + 6)
- D. 4x - 3 + 6
Correct Answer & Rationale
Correct Answer: C
The phrase describes a mathematical expression involving a number, denoted as \( x \). "Three less than a number" translates to \( x - 3 \), while "six more than four times a number" translates to \( 4x + 6 \). Therefore, the entire expression is the quotient of these two parts, resulting in \( \frac{x - 3}{4x + 6} \), which matches option C. Option A incorrectly suggests a subtraction in the numerator, altering the intended expression. Option B implies multiplication instead of division, misrepresenting the relationship. Option D presents a simplified expression rather than a quotient, which does not align with the original phrase.
The phrase describes a mathematical expression involving a number, denoted as \( x \). "Three less than a number" translates to \( x - 3 \), while "six more than four times a number" translates to \( 4x + 6 \). Therefore, the entire expression is the quotient of these two parts, resulting in \( \frac{x - 3}{4x + 6} \), which matches option C. Option A incorrectly suggests a subtraction in the numerator, altering the intended expression. Option B implies multiplication instead of division, misrepresenting the relationship. Option D presents a simplified expression rather than a quotient, which does not align with the original phrase.
Factor completely: b^2 + 3b - 4
- A. (b + 4)(b - 1)
- B. (b - 2)(b - 3)
- C. (b + 1)(b + 2)
- D. (b + 3)(b - 1)
Correct Answer & Rationale
Correct Answer: A
To factor the expression \( b^2 + 3b - 4 \), we need two numbers that multiply to \(-4\) (the constant term) and add to \(3\) (the coefficient of \(b\)). The numbers \(4\) and \(-1\) satisfy these conditions, leading to the factors \( (b + 4)(b - 1) \). Option B, \( (b - 2)(b - 3) \), yields \( b^2 - 5b + 6\), which does not match the original expression. Option C, \( (b + 1)(b + 2) \), results in \( b^2 + 3b + 2\), also incorrect due to the wrong sign on the constant term. Option D, \( (b + 3)(b - 1) \), gives \( b^2 + 2b - 3\), which again does not match. Thus, only option A correctly factors the expression.
To factor the expression \( b^2 + 3b - 4 \), we need two numbers that multiply to \(-4\) (the constant term) and add to \(3\) (the coefficient of \(b\)). The numbers \(4\) and \(-1\) satisfy these conditions, leading to the factors \( (b + 4)(b - 1) \). Option B, \( (b - 2)(b - 3) \), yields \( b^2 - 5b + 6\), which does not match the original expression. Option C, \( (b + 1)(b + 2) \), results in \( b^2 + 3b + 2\), also incorrect due to the wrong sign on the constant term. Option D, \( (b + 3)(b - 1) \), gives \( b^2 + 2b - 3\), which again does not match. Thus, only option A correctly factors the expression.
The owner of a small cookie shop is examining the shop's revenue and costs to see how she can increase profits. Currently, the shop has expenses of $41.26 and $0.19 per cookie.
The shop's revenue and profit depend on the sales price of the cookies. The daily revenue is given in the graph below, where x is the sales price of the cookies and y is the expected revenue at that price.
The shop owner needs to determine the total daily cost of making x cookies. Which of the following linear equations represents the cost, C, in dollars?
- A. C=4.6x+995
- B. C=0.046x+2
- C. C=0.19x+41.26
- D. C=1.2x+212.26
Correct Answer & Rationale
Correct Answer: C
The equation representing total daily cost must account for both fixed and variable costs. The fixed cost of $41.26 reflects the shop's expenses, while the variable cost is $0.19 per cookie, leading to the term 0.19x for x cookies. Therefore, C = 0.19x + 41.26 accurately captures both components. Option A incorrectly suggests a much higher fixed cost and variable rate, implying unrealistic expenses. Option B has a fixed cost that is too low and a variable cost that is also incorrect. Option D presents exaggerated figures for both fixed and variable costs, misrepresenting the shop's actual expenses.
The equation representing total daily cost must account for both fixed and variable costs. The fixed cost of $41.26 reflects the shop's expenses, while the variable cost is $0.19 per cookie, leading to the term 0.19x for x cookies. Therefore, C = 0.19x + 41.26 accurately captures both components. Option A incorrectly suggests a much higher fixed cost and variable rate, implying unrealistic expenses. Option B has a fixed cost that is too low and a variable cost that is also incorrect. Option D presents exaggerated figures for both fixed and variable costs, misrepresenting the shop's actual expenses.