Algebra B
Unit 5 Part 2 – Sections 5.9 and 5.10
REVIEW
1
Name ______________________________________________
LT 5.9 Given a real world situation represented by a quadratic function, I can evaluate the
function for specific values of the domain.
#1 Physics. A boat fires an emergency flare that travels upward at an initial velocity of 25 meters per
second. To find the height in meters, h, of the flare at t seconds, use the function:
h = -5t2 + 25t
a) At what time will the flare reach
its maximum height? (show work)
b) What is the flares maximum height?
(show work)
c) How long does it take the flare to
reach the ocean surface? (show work)
d) When is the flare 10m above
the ocean? (show work)
e) Use the answers from parts a through d
to draw the graph of the function. (graph paper)
f) State the domain and range of the function.
(use the correct variables)
Algebra B
Unit 5 Part 2 – Sections 5.9 and 5.10
REVIEW
2
#2 Accounting. To approximate the profit per day for her business, Poly Graf uses the formula given below.
The profit, p, depends on the number of cases, x, of decorator napkins that are sold.
p = -x2 + 50x – 350
a) How many cases of napkins must she
sell to break even? (p = 0) (show work)
b) What is her profit is she doesn’t sell any
cases of napkins? (show work)
c) How many cases of napkins must she
sell to make the maximum profit? (show work)
d) Find the maximum profit. (show work)
e) Use the answers from parts a through d
to draw the graph of the function. (graph paper)
f) State the domain and range of the function.
(use the correct variables)
Algebra B
LT 5.10
Unit 5 Part 2 – Sections 5.9 and 5.10
REVIEW
3
I can write and solve a quadratic equation for real world situations.
#3 Geometry. The length of a rectangular flag is 4 yards longer than the width. The area of the flag is 140
square yards. Write and solve an equation to find the length and width. (show work and define your
variables.)
#4 Photography. The area of a rectangular photograph is 396 square centimeters. Write and solve an
equation to find the dimensions of the photograph is the length is 4 cm more than the width. (show work and
define your variables.)
#5 Geometry. The dimensions of a rectangle were 8 units by 15 units. Each dimension was increased by
the same amount. The rectangle then had an area of 198 units².
What was the amount by which each dimension was increased? And what are the dimensions of the new
rectangle?
Algebra B
#1
Unit 5 Part 2 – Sections 5.9 and 5.10
REVIEW
4
Algebra B
#2
Unit 5 Part 2 – Sections 5.9 and 5.10
REVIEW
5
Algebra B
Unit 5 Part 2 – Sections 5.9 and 5.10
REVIEW
#3
#4
#5
x
8
x
15
( x + 8)(x + 15) = 198
FOIL
x² + 8x + 15x + 120 =198
x² + 23x + 120 =198
-198 -198
x² + 23x - 78 = 0
Factor
( x – 3) ( x + 26 ) = 0
x – 3 = 0 x + 26 = 0
x=3
x = -26
x + 8 = 3 + 8 = 11
x + 15 = 3 + 15 = 18
Therefore, the rectangle increased by 3
units. The new dimensions are now 11
units by 18 units.
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