1. Lesson 1­8.notebook September 24, 2012
Assignment:
1­­>L1.8, pg. 56­57, #3­39 (thirds)
2­­>Checkpoint 1.5­1.7 Due Thursday (9/27)
3­­>Chapter 1 Test ­ Thursday
(9/27)
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2. Lesson 1­8.notebook September 24, 2012
Lesson 1.8 WarmUp:
1) Evaluate: (­5)3
2) Is the relation a function? Explain.
{(0, 2), (3, 5), (0, ­1), (­2, 4)}
3) Write a verbal expression for 4y + 2
4) Find the surface area of a rectangular prism with sides
10 cm, 15 cm, and 12 cm.
5) Find the volume of the rectangular prism in #4
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3. Lesson 1­8.notebook September 24, 2012
Lesson 1.8:
*conditional statement­­>a statement that can be written in the form:
"If A, then B". [also called if­then statements]
ex­­>"If an insect is a butterfly, then it was a caterpillar"
*hypothesis ­­>the part of the statement immediately following the "IF"
*conclusion ­­>the part of the statement immediately following the
"THEN"
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4. Lesson 1­8.notebook September 24, 2012
FYI...If a conditional statement is true, the hypothesis doesn't
always have to be true.
i.e....If Sam plays air hockey, then he is at an arcade.
But...just because Sam is at an arcade,
does not mean that he plays air hockey.
*deductive reasoning ­>the process of using facts, rules, definitions,
or properties to reach a valid conclusion
*counterexample ­>a specific case in which the hypothesis is true
and the conclusion is false
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5. Lesson 1­8.notebook September 24, 2012
Lesson 1.8 examples:
Identify the hypothesis and conclusion of each statement.
A) If we have enough sugar, then we will make cookies.
h ­>we have enough sugar
c ­>we will make cookies
B) if 16x ­ 5 = 43, then x = 3
h ­>16x ­ 5 = 43
c ­>x = 3
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6. Lesson 1­8.notebook September 24, 2012
Identify the hypothesis and conclusion of each statement. Then write each
statement in "if­then" form.
C) The neon light is on when the store is open.
h ­>the store is open
c ­>the neon light is on
if­then ­>If the store is open, then the neon light is on
D) A circle with a radius of w ­ 4 has a circumference of 2 (w ­ 4)
h ­>a circle with a radius of w ­ 4
c ­>has a circumference of 2 (w ­ 4)
if­then ­>If a circle has a radius of w ­ 4, then it has a
circumference of 2 (w ­ 4)
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7. Lesson 1­8.notebook September 24, 2012
Determine a valid conclusion from the statement: "If one number is
negative and another is positive, then their product must be
negative". If a valid conclusion doesn't follow, write no valid
conclusion and explain.
E) the numbers are ­3 and 4
one is negative and one is positive, so the hypothesis is true...
their product is ­12, so the conclusion is also true.
F) the product is 10
the product is positive, so the conclusion is not true...therefore
there is no valid conclusion.
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8. Lesson 1­8.notebook September 24, 2012
Find a counterexample for each conditional statement.
G) if ab >0, then a and b are greater than 0.
(­5)(­3) is greater than 0, but neither of those are greater than 0
H) If a clothing store is selling wool coats, then it must be December.
The store could be selling coats in September...to prepare for
cold weather in December.
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