8th grade Ch 4 L3

Find f(4) if f(x) = x - 6.

• -2

• 2

• -10

• 10

Choose four values for x to make a function table for f(x) = 8 - x. Then state the domain and range of the function.

• Sample values: x = 0, 2, 4, 8. Table: x: 0, 2, 4, 8; 8-x: 8, 6, 4, 0; f(x): 8, 6, 4, 0. Domain: {0, 2, 4, 8}. Range: {0, 4, 6, 8}.

• Sample values: x = 1, 3, 5, 7. Table: x: 1, 3, 5, 7; 8-x: 7, 5, 3, 1; f(x): 7, 5, 3, 1. Domain: {1, 3, 5, 7}. Range: {1, 3, 5, 7}.

• Sample values: x = 2, 4, 6, 8. Table: x: 2, 4, 6, 8; 8-x: 6, 4, 2, 0; f(x): 6, 4, 2, 0. Domain: {2, 4, 6, 8}. Range: {0, 2, 4, 6}.

• Sample values: x = 0, 1, 2, 3. Table: x: 0, 1, 2, 3; 8-x: 8, 7, 6, 5; f(x): 8, 7, 6, 5. Domain: {0, 1, 2, 3}. Range: {5, 6, 7, 8}.

A hot air balloon can hold 90,000 cubic feet of air. It is being inflated at a rate of 6,000 cubic feet per minute. The total cubic feet of air a(t) is a function of the time in minutes t. Identify the independent and dependent variables.

• Independent variable: time (t); Dependent variable: total cubic feet of air (a(t))

• Independent variable: total cubic feet of air (a(t)); Dependent variable: time (t)

• Independent variable: rate of inflation; Dependent variable: time (t)

• Independent variable: total cubic feet of air (a(t)); Dependent variable: rate of inflation

Which values of the domain and range make sense for this situation?

• Domain: all real numbers; Range: all real numbers

• Domain: only positive integers; Range: only positive integers

• Domain: only negative numbers; Range: only negative numbers

• Domain: only zero; Range: only zero

A hot air balloon can hold 90,000 cubic feet of air. It is being inflated at a rate of 6,000 cubic feet per minute. The total cubic feet of air a(t) is a function of the time in minutes t. Write a function to represent the total amount of air. Then determine the total amount of air in 6 minutes.

• a(t) = 6,000t; a(6) = 36,000 cubic feet.

• a(t) = 15,000t; a(6) = 90,000 cubic feet.

• a(t) = 90,000t; a(6) = 540,000 cubic feet.

• a(t) = 1,500t; a(6) = 9,000 cubic feet.

The domain of a function determines which values are possible in the range.

• The domain of a function determines which values are possible in the range.

• The range of a function determines the domain.

• The domain and range are always the same.

• The domain does not affect the range at all.

Choose four values for x to make a function table for the function f(x) = 6x - 4. Then state the domain and range of the function. Fill in the table: x | 6x - 4 | f(x) ___|_______|_____ ___|_______|_____ ___|_______|_____ ___|_______|_____

• Sample values: x = 0, 1, 2, 3. f(x) = -4, 2, 8, 14. Domain: all real numbers. Range: all real numbers.

• Sample values: x = 0, 1, 2, 3. f(x) = -4, 2, 6, 10. Domain: positive integers. Range: positive integers.

• Sample values: x = -1, 0, 1, 2. f(x) = -10, -4, 2, 8. Domain: integers only. Range: integers only.

• Sample values: x = 1, 2, 3, 4. f(x) = 2, 8, 14, 20. Domain: x > 0. Range: f(x) > 0.

Choose four values for x to make a function table for the function f(x) = 5 - 2x. Then state the domain and range of the function. Fill in the table: x | 5 - 2x | f(x) ___|_______|_____ ___|_______|_____ ___|_______|_____ ___|_______|_____

• Sample values: x = 0, 1, 2, 3. f(x) = 5, 3, 1, -1. Domain: all real numbers. Range: all real numbers.

• Sample values: x = 0, 1, 2, 3. f(x) = 5, 7, 9, 11. Domain: positive integers. Range: positive integers.

• Sample values: x = -1, 0, 1, 2. f(x) = 7, 5, 3, 1. Domain: integers only. Range: integers only.

• Sample values: x = 1, 2, 3, 4. f(x) = 3, 1, -1, -3. Domain: x > 0. Range: f(x) < 5.

Choose four values for x to make a function table for the function f(x) = 7 + 3x. Then state the domain and range of the function. Fill in the table: x | 7 + 3x | f(x) ___|_______|_____ ___|_______|_____ ___|_______|_____ ___|_______|_____

• Sample values: x = 0, 1, 2, 3. f(x) = 7, 10, 13, 16. Domain: all real numbers. Range: all real numbers.

• Sample values: x = 0, 1, 2, 3. f(x) = 7, 8, 9, 10. Domain: positive integers. Range: positive integers.

• Sample values: x = -1, 0, 1, 2. f(x) = 4, 7, 10, 13. Domain: integers only. Range: integers only.

• Sample values: x = 1, 2, 3, 4. f(x) = 8, 11, 14, 17. Domain: x > 0. Range: f(x) > 0.

In a recent 82-game season, Dwight Howard of the Orlando Magic averaged 20.7 points per game. His approximate total points scored p(g) is a function of the number of games played g. Which of the following correctly identifies the independent and dependent variables in this context?

• Independent variable: number of games played; Dependent variable: total points scored

• Independent variable: total points scored; Dependent variable: number of games played

• Independent variable: average points per game; Dependent variable: number of games played

• Independent variable: average points per game; Dependent variable: total points scored