Contains the phrase “if & only if” Abbr. iff It is a conditional statement & its

converse all in one. Ex: 3 points are collinear iff they are on

the same line. Conditional: If 3 pts are collinear, then

they are on the same line. Converse: If 3 pts are on the same line,

then they are collinear.

x=3 if and only if x2=9. Yes, it’s a biconditional.Orig. Conditional statement? If x=3, then x2=9.Converse? If x2=9, then x=3.True or False? Biconditional is False

True

False, x could be -3

Conditional: If a # ends in 0 or 5, then it is evenly divisible by 5.

Converse: If a # is evenly divisible by 5, then it ends in 0 or 5.

True or False?Biconditional?A # ends in 0 or 5 iff it is divisible by 5.

TrueTrue

TrueTrue

•Definitions can be written in “if-then” form.

•The converse of a definition is always true.

•This means the defn. is true forwards & backwards.

BICONDITIONAL!!!

Show that the definition of right angle is reversible. Then write it as a biconditional.

•Definition: A right angle is an angle whose measure is 90.

An angle is a right angle then the angle measures 90 degrees

An angle is 90 degrees then it is a right angle

Conditional: Conditional:

Converse: Converse:

True

BiconditionalBiconditional

An angle is a right angle iff it measures 90 degrees

All rights belong to their respective owners.Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, TEACHING, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, EDUCATIONAL or personal use tips the balance in favor of fair use.