Conditional Statements

·What is the purpose of the previous sentence?It gives two reasons why the popcorn might burn.

·Does this mean the popcorn will burn? Explain.No: the sentence begins with "if"

·Suppose the heat is too high. What does the sentence tell you about this situation?The popcorn will likely burn.

·Conditional StatementsCan be written in the form If A, then B.

If the popcorn burns, then the heat was too high or the kernels heated unevenly

The Hypothesis is the part of the statement immediately following "If"The Conclusion if the part of the statement immediately following "then"

Identify the hypothesis and conclusion of each statement. The write each statement in "if-then" form.

·I will go to the ball game with you on SaturdayHypothesis: it is SaturdayConclusion: I will go to the ball game with you

If it is Saturday, then I will go to the ball game with you.

·For a number x such that 6x - 8 = 16, x = 4Hypothesis: 6x - 8 = 16Conclusion: x = 4

If 6x - 8 = 16, then x = 4

·Brianna wears goggles when she is swimmingHypothesis: Brianna is swimmingConclusion: she wears goggles

If Brianna is swimming, then she wearing goggles

Identify the hypothesis and conclusion of each statement. Then write each statement in "if-then" form.

·Colin watches television when he does not have homework.Hypothesis: Colin does not have homeworkConclusion: he watches televisionIf Colin does not have homework, then he watches television.

·A number that is divisible by 10 is also dividible by 5Hypothesis: a number is divisible by 10Conclusion: it is divisible by 5If a number is divisible by 10, then it is divisible by 5

·A rectangle is a quadrilateral with four right angles.Hypothesis: a quadrilateral with four right anglesConclusion: rectangleIf a quadrilateral with four right angles, then it is a rectangle.

Deductive Reasoning

·Deductive Reasoning is the process of using facts, rules, definitions, or properties to reach a valid conclusion.

Determine a valid conclusion that follows from the statement below for each condition. If a valid conclusion does not follow, write "no valid conclusion" and explain why.

"If two numbers are odd, then their sum is even."· The two numbers are 7 and 3

7 and 3 are odd, so the jypothesis is true.Conclusion: the sum of 7 and 3 is even

·The sum of two numbers is 14The conclusion is true. If the numbers are 11 and 3, the

hypothesis is true also. However, if the numbers are 8 and 6, the hypothesis is false. Therefore, there is no valid conclusion that

can be drawn from the given conditional.

Determine a valid conclusion that follows from the statement below for each given condition. If a valid conclusion does not follow, write "no valid conslusion" and explain why.

If the last digit of a number is 2, then the number is divisble by 2.

·The number is 10, 452. The number is divisible by 2.

·The number is divisible by 2. No valid conclusion: the last digit could be any even number.

·The number is 946. No valid conclusion; the last digit is 6.

Determine a valid conclusion that follows from the statement below for each condition. "There will be a quiz every Wednesday."

It is Wenesday There will be a quiz.

It is Tuesday There will might not be a quiz today.

Determine a valid conclusion that follows from the statement below for each condition. If a valid conclusion does not follow, write "no valid conclusion" and explain why.

If one number is odd and another number is even, then their sum is odd.

·The two numbers are 5 and 12.5 is odd and 12 is even, and 5 + 12 = 17.Conclusion: The sum of 5 and 12 is odd.

·The two numbers are 8 and 26.8 and 26 are both even so the hypothesis is false. No valid

conclusion.

Counterexamples

A Counterexample is a specific case in which the hypothesis is true and the conclusion is false. It only takes one counterexample to show that a statement is false.

·"If a triangle has a perimeter of 3 cm, then each side measures 1 cm."Counterexample: The sides are 0.9cm, 0.9cm, and 1.2 cm.

·Which numbers are counterexamples to the following statement?x - y ≠y - x

A) x = 2, y = 3 B) x = 4, y = 4C) x = 0, y = 1 D) x = 7, y = -7

B

·Which numbers disprove the statement below?If x + y > xy, then x>y

F) x = 1, y = 2 G) x = 2, y = 3H) x = 4, y = 1 J) x = 4, y = 2

F

Find a counterexample for each conditional statement

·If Anna is in school, then she has a science class.Anna has a schedule without a science class.

·If you can read 8 pages in 30 minutes, then you can read a book in a day.A book can have more than 384 pages

·If a number x is squared, then x2 > x x = 1

·If 3x + 7 ≥ 52, then x > 15 x = 15