Chapter 6: Q3. (page 215)
What is the first sentence of an indirect proof of the statement shown?
Doug is a Canadian.
Short Answer
The first sentence of an indirect proof of the statement 鈥淒oug is a Canadian.鈥 is鈥淎ssume that Doug is not a Canadian.鈥
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 6: Q3. (page 215)
What is the first sentence of an indirect proof of the statement shown?
Doug is a Canadian.
The first sentence of an indirect proof of the statement 鈥淒oug is a Canadian.鈥 is鈥淎ssume that Doug is not a Canadian.鈥
All the tools & learning materials you need for study success - in one app.
Get started for free
Complete the following statement with the word always, sometimes, or never.
Two lines parallel to a third line are _____ parallel.
Arrange sentences (a)-(e) in an order that completes an indirect proof of the following statement: In a plane, two lines perpendicular to a third line are parallel to each other.
Given: Lines a, b and t lie in a plane;
Prove:
(a) Then a intersects b in some point Z.
(b) But this contradicts the theorem which says that there is exactly one line perpendicular to a given line through a point outside the line.
(c) It is false that a is not parallel to b, and it follows that
(d) Assume temporarily that a is not parallel to b.
(e) Then there are two lines through Z and perpendicular to t.

Write an indirect proof in paragraph form.
Given:
Prove: is not a right angle.

Suppose someone plans to write an indirect proof of each conditional. Write a correct first sentence of the indirect proof.
If , then
A certain conditional is false. Must its converse be false? Must its inverse be false? Must its contrapositive be false?
What do you think about this solution?
We value your feedback to improve our textbook solutions.