Math 8 Function Review

Remember:
y=mx+b

What is the slope of the line defined by the

following equation:

y = -3x + 2

☺

-2

-3x

-3

slope=

What is the rate of change (slope)
for the above data table?

change in x

change in y

(Read slope from
left to right)

Positive

Negative

Is the slope
positive or
negative?

-2

1/2

-1/2

Calculate the slope of the line that passes

through the points (1, -2) and (5, 6).

(1,-2) (5,6)

"Slope Superman"

Calculate the slope of the line that passes

through the points (1, -2) and (5, 6).

"Slope Superman"

(1,-2) (5,6)

6 - (-2) = 8

5 - 1 = 4

= 2

What is the slope of

the line segment?

Look at me!!!
Same line...

2/3

-3/2

-2/3

3/2

slope=

What is the rate of change for the above data table?

change in y

change in x

(Reduce or else!!!)

Proportional Graphs

ALWAYS pass through
the origin

All of these lines
show direct
variation

○

Proportional,
it passes through (0,0)

This Graph is

Find k, which is
(the multiplier,
the slope, y/x)

y=kx

Which of the

graphs

represents a

direct variation?

(A Proportional Relationship)

Which lines

have positive

m values

(positive slopes?)

SELECT ALL

Which lineshave NEGATIVE m values(negative slopes?)

SELECT ALL

Which lineshave negativem (slope) andb (y-intercept)values?

SELECT

ALL

Approximate these SLOPES (m)

≈ means APPROXIMATELY equal to

Slope ≈ -.99

Slope ≈.66

Slope ≈.01

Describe these SLOPES (m)

Negative Slope

Positive Slope

Zero Slope

Which y-intercept is greatest?

Greatest y-Intercept

Medium y-intercept

Least y-intercept

only increases

only decreases

is constant

increases and
decreases

This graph:

Number of legs

increases

decreases

is constant

increases and
decreases

From zero legs
to two legs, this
graph:

Number of legs

increases

decreases

is constant

increases and
decreases

From two legs
to three legs,
this graph:

Number of legs

(0,2)

(3,4) : 3<x<4

(4,8) : 4<x<8

On which interval
does the graph
NOT increase?

: 0<x<2

Number of legs

(creepy,cute)

(kill it, creepy)

(kill it, awww)

(0,8)

What is the range?

Number of legs

only increases

only decreases

is constant

is constant and
decreases

This graph:

3 ≤ x ≤ 5

1< x < 3

2< x < 5

Where does

this graph
decrease?

[1,3]

[3,5]

[1,5]

[0,3]

The domain
(possible x values)
of this graph is:

The x axis is
shaded according
to the increase
and decrease
of the graph.

The graph (the curve)
is increasing when the
x-axis is shaded:

green

The graph (the curve)
is decreasing when the
x-axis is shaded:

red

The x axis is
shaded according
to the increase
and decrease
of the graph.

The graph (the curve)
is increasing from

( -1, ∞ )

The graph (the curve)
is decreasing from

( -∞ , -1)

41. You called the plumber. Again. The plumber charges $160 after 2 hours, and charges $210 after 3 hours. What linear equation, C(h), shows what the plumber charges after h hours?

A) C(h) = 70h + 60
B) C(h) = 70h
C) C(h) = 50h + 60
D) C(h) = 60h + 50
E) C(h) = 80h

42. A woman makes designer napkins. She hand delivers them for a set price. A one napkin shipment costs $175. A three napkin shipment costs $225. Write a function to show C(n), the cost for fancy napkin delivery..

A) C(n) = 25n + 150
B) C(n) = 50n + 125
C) C(n) = 175n
D) C(n) = 150n + 25
E) C(n) = 75n