Statements patterns and Logical Equivalence

IMPORTANT

Statements patterns and Logical Equivalence: Overview

This topic covers concepts, such as, Direct Method for Validity of a Statement, Tautology in Mathematical Reasoning, Counter Example Method for Validity of a Statement and Contrapositive Method for Validity of a Statementetc.

Important Questions on Statements patterns and Logical Equivalence

EASY
IMPORTANT

The statement (p(~q))((~p)  q) ((~p)  (~q)) is equivalent to _____

EASY
IMPORTANT

Among the statements

S1: pq~pq is a tautology

S2: qp~pq is a contradiction

MEDIUM
IMPORTANT

Contrapositive of statement pattern ~pqp~q is

EASY
IMPORTANT

Number of the form 2 n + 1 where n is any positive integer are always odd number.

HARD
IMPORTANT

By giving a counter example, show that the following statement is false. If n is an odd integer, then n is prime.

HARD
IMPORTANT

Verify by the method of contradiction.

p:7 is irrational

MEDIUM
IMPORTANT

Check whether the following statement is true or false by proving its contrapositive. If x, yZ such that xy is odd, then both x and y are odd.

MEDIUM
IMPORTANT

Check whether the following statement is true or not. If x, yZ are such that x and y are odd, then xy is odd.

MEDIUM
IMPORTANT

State whether the following statement is true or false.

The PQ and ¬PQ relations are logically equivalent.

MEDIUM
IMPORTANT

Show that PQ and ¬PQ are logically equivalent.

MEDIUM
IMPORTANT

Find if  ~AB  ~(AB) is a tautology or not.

MEDIUM
IMPORTANT

 Show that p(pq) is a tautology.

MEDIUM
IMPORTANT

Consider the statement:

q: for any real number a & ba2=b2a=b.

By giving a counterexample, prove that q is false.

MEDIUM
IMPORTANT

By giving a counterexample, show that the following statement is not true.

q: The equation x2-1=0 does not have a root lying between 0 & 2.

MEDIUM
IMPORTANT

Check the validity of the statement given below by the method given against it.

q: If nis a real number with n>3, then n2>9 (By contradiction method)

MEDIUM
IMPORTANT

Show that the statement p: If x is a real number such that x3+4x=0, then x is 0 is true by the method of contradiction.

MEDIUM
IMPORTANT

Show that the statement p: If x is a real number such that x3+4x=0, then x is 0 is true by the method of contrapositive.

MEDIUM
IMPORTANT

Let p:If x is an integer and x2 is even, then x is even. Using the method of contrapositive, prove that p is true.

MEDIUM
IMPORTANT

Check the validity of the compound statement using the direct method.

If x is a number such that 2x3+5x=0, then x=0.

MEDIUM
IMPORTANT

Check the validity of the compound statement using the direct method.

If x is a number such that 4x3+3x=0, then x=0.