Functions
Suppose a function relates hours worked to earnings. The earnings would be considered the (independent/dependent) variable.
y = 2x + 6 is an example of a linear equation is what form?
Slope - intercept form
Find the x-intercept of the equation 3x + 4y = 24.12
8.04
Solve:
15h - 3(2h - 6) = -9
h = -3
Solve and graph
7-6n < 5n + 40
-3 < n
Suppose f(x) = 4x -3. Then which of the following is true?
a. F(0) = -3
b. f(0) = 3/4
c. f(-3) = -9
d. f(1/4) = -2
A and D
4x + 6y = 13 is an example of a linear equation in what form?
STANDARD
Calculate the slope of the line that passes through the points (-2,11) and (4, -13)
m = -4
Solve:
6x-4(-3x - 4) = 4(5x) -2x + 16
Infinite solutions
Solve the compound inequality and graph the solution:
-18< -3x + 3 < 24
7 > x > -7
Give an example of a function with a domain of (2,4,6.)
Answers may vary. However, every input (domain) should have only one unique output (range)
Suppose a cell phone contract provides unlimited calling for $10 per month "access fee" but charges $.05 per text sent or received. Write an equation that expresses the total cost (C) in dollars for a months cell usage under this contract as a function of the number of texts (t) sent. Include a verbal model.
Verbal Model:
Total Cost = cost per text + monthly access fee
Equation:
C = .05t + 10
Provide a slope that is parallel and a slope that is perpendicular to an equation with a slope of 3.
Parallel = 3
Perpendicular = -1/3
Suppose Casey is making a scale model of his bedroom using a scale 1in:3ft. Write and solve a proportion to find the height of the ceiling in the model if the actual height is 10 ft.
3 1/3 inches
Simplify:
20/5 x 6 - 5 x 23 + 52 - (9-5)2
-7
Using the domain of (2, 4, 6) provide an example of a relation which is not a function and explain why it is not a function.
Answer should include in input that has multiple outputs attached to it. It is not a function because in a function, every input has only one unique output.
Write an equation of the line that passes through the points (-2, -2) and (6, -8)
y=-3/4x - 3.5
What is the slope and y-intercept of the equation
y-2 = 1/3(x + 1)
Slope = 1/3
Y-intercept (2 1/3)
Solve:
8/2x + 4 = 5/3x -1
x = 2
Suppose 2x - 12 = 45. Which property tells us that 2x -12 + 12 = 45 + 12
Addition property of equality
Given a graph of a function, how do you determine if the function is continuous?
If there is a line that connects the points on the graph.
No
Graph y= (-1/4)x + 2 in the coordinate plan. Identify the y-intercept and the slop, and use that information to complete the graph.
m = -1/4
b = 2
See Miss N for graph
Solve:
3(4x + 2) = 4(3x + 3)
No Solutions
Which equation represents direct variation?
a. (-1/3)x - y = 0
b. 2y - x = 3
c. 2y = (2/5)x
d. y = (1/2)x + 12
a and c