Question

Question 15 Unsaved Which biconditional is NOT a good definition? Question 15 options: A whole number is odd if and only if the number is not divisible by 2. A ray is a bisector of an angle if and only if it splits the angle into two angles. An angle is straight if and only if its measure is 180. A whole number is even if and only if it is divisible by 2.

Answer 1

We see that the second definition is not a good definition. We want both parts to have the same truth value, but we see that we can have two angles created by a ray that are not equal. That means the antecedent is false but the consequence is true, which means it's not an iff statement, and a bad definition in this context.