QZ10: Study Guide of Test Unit 3: Functions

The graph of a relation is shown at the right. Is this relation a function?

• Yes

• No

• Cannot be determined from a graph

Answer explanation

Some x-values have more than one y-values, and so this relation is not a function.

Which equation matches the table?

• y = 3x + 9

• y = x + 9

• y = x + 3

• y = 12x - 3

Answer explanation

The initial value is 9, when x = 0.
The rate of change is $\frac{12-9}{1-0}=3$

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

Find the rate of change

• 1

• 2

• 11

• Not a constant slope/Non-Linear

Answer explanation

$\frac{\Delta y}{\Delta x}=\frac{13-11}{2-1}=2$

Tags

CCSS.8.F.B.4

CCSS.HSF.IF.B.6

Identify the rate of change from the following equation:

y = 2x + 4

• 1

• 2

• 3

• 4

Answer explanation

In the formula y=mx+b, m is the rate of change.

2 is in the position of m.

Tags

CCSS.HSF-LE.A.1B

Select all the ways that describe the graph of the function in interval E.

• The function is increasing.

• The slope is negative.

• The function is decreasing.

• The function is constant.

• The slope is positive.

Answer explanation

From left to right, Interval E is going down and so it is decreasing and the slope is negative.

Tags

CCSS.HSF.IF.B.4

What is an equation for the line that passes through the coordinates (2,7) and (0, 1)?

• y = 3x + 1

• y = 1x + 3

• y = x - 3

• y = -x + 3

Answer explanation

$m=\frac{y_2-y_1}{x_2-x_1}=\frac{7-1}{2-0}=\frac{6}{2}=3$
$7=3\cdot2+b\ solve\ for\ b,\ b=1$
y=3x+1

Is this graph a function or not a function?

• Function

• Not a Function

Answer explanation

One x-value has two y-values, and so this relation is not a function.

Tags

CCSS.8.F.A.1

What is the greater rate of change?

• 
• 
• If you start with 60 points and get 1 point per assignment.

• y = 1x + 50

• They're all the same!

Answer explanation

The rate of change for all the four representations is 1.

Tags

CCSS.8.F.B.4

CCSS.HSF.IF.B.6

What is the initial value of the graph?

• 4

• 8

• -4

• -8

Find the initial value of the table.

• 11

• 2

• 9

• 1

Answer explanation

When x = 0, the y is 11-2=9.

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2