Negasi Konvers Invers 549D24
1. Problem: Write the negation, converse, inverse, and contrapositive of the implication and determine the truth value for each.
2. Definitions:
- Original implication: $p \to q$
- Negation: $p \wedge \neg q$
- Converse: $q \to p$
- Inverse: $\neg p \to \neg q$
- Contrapositive: $\neg q \to \neg p$
3. a. "If 10 is a prime number then 10 divides 30."
- $p$: 10 is prime
- $q$: 10 divides 30
Negation: 10 is prime and 10 does not divide 30.
Truth: False (10 divides 30)
Converse: If 10 divides 30 then 10 is prime.
Truth: False (10 divides 30 but 10 is not prime)
Inverse: If 10 is not prime then 10 does not divide 30.
Truth: False (10 is not prime but 10 divides 30)
Contrapositive: If 10 does not divide 30 then 10 is not prime.
Truth: True (contrapositive always has same truth as original)
Original implication truth: True (10 is not prime but the implication is true because the antecedent is false)
4. b. "A quadrilateral is a square if and only if its diagonals are equal in length."
- $p$: Quadrilateral is a square
- $q$: Diagonals are equal
This is a biconditional $p \leftrightarrow q$.
Negation: Quadrilateral is a square and diagonals are not equal, or quadrilateral is not a square and diagonals are equal.
Truth: False (both directions are true for squares)
Converse: Same as original because biconditional.
Truth: True
Inverse: If not square then diagonals not equal.
Truth: False (some non-square quadrilaterals have equal diagonals)
Contrapositive: If diagonals not equal then not square.
Truth: True
Original biconditional truth: True
5. c. "If adjacent sides of a quadrilateral are equal then the quadrilateral is a rhombus."
- $p$: Adjacent sides equal
- $q$: Quadrilateral is rhombus
Negation: Adjacent sides equal and quadrilateral is not rhombus.
Truth: False (if adjacent sides equal but not rhombus is false)
Converse: If quadrilateral is rhombus then adjacent sides equal.
Truth: True
Inverse: If adjacent sides not equal then quadrilateral is not rhombus.
Truth: True
Contrapositive: If quadrilateral is not rhombus then adjacent sides not equal.
Truth: True
Original implication truth: True
Final answers:
For a:
- Negation: False
- Converse: False
- Inverse: False
- Contrapositive: True
- Original: True
For b:
- Negation: False
- Converse: True
- Inverse: False
- Contrapositive: True
- Original: True
For c:
- Negation: False
- Converse: True
- Inverse: True
- Contrapositive: True
- Original: True