Advertisements
Advertisements
प्रश्न
Show that the statement “For any real numbers a and b, a2 = b2 implies that a = b” is not true by giving a counter-example.
Advertisements
उत्तर
The given statement can be written in the form of “if-then” as follows.
If a and b are real numbers such that a2 = b2, then a = b.
Let p: a and b are real numbers such that a2 = b2.
q: a = b
The given statement has to be proved false. For this purpose, it has to be proved that if p, then ∼q. To show this, two real numbers, a and b, with a2 = b2 are required such that a ≠ b.
Let a = 1 and b = –1
a2 = (1)2 = 1 and b2 = (– 1)2 = 1
∴ a2 = b2
However, a ≠ b
Thus, it can be concluded that the given statement is false.
APPEARS IN
संबंधित प्रश्न
Find out the sentence are statement and are not. Justify your answer.
Every rhombus is a square.
Find out the sentence are statement and are not. Justify your answer.
All real numbers are complex numbers.
Write the negation of the statement:
The earth is round.
There is a complex number which is not a real number.
Are the pair of statement are negation of each other:
The number x is not a rational number.
The number x is an irrational number.
Find the component statement of the compound statement:
The sky is blue and the grass is green.
Find the component statement of the compound statement:
All rational numbers are real and all real numbers are complex.
Write the component statement of the compound statement and check whether the compound statement is true or false:
To enter into a public library children need an identity card from the school or a letter from the school authorities.
Determine whether the compound statement are true or false:
Delhi is in England and 2 + 2 = 4.
Determine whether the compound statement are true or false:
Delhi is in India and 2 + 2 = 5.
Write of the statement in the form "if p, then q".
The game is cancelled only if it is raining.
Write of the statement in the form "if p, then q".
It never rains when it is cold.
statement are true and false? In each case give a valid reason for saying so
p : Each radius of a circle is a chord of the circle.
statement are true and false? In each case give a valid reason for saying so
q : The centre of a circle bisects each chord of the circle.
statement are true and false? In each case give a valid reason for saying so
r : Circle is a particular case of an ellipse.
statement are true and false? In each case give a valid reason for saying so
t : \[\sqrt{11}\] is a rational number.
Determine whether the argument used to check the validity of the following statement is correct:
p : "If x2 is irrational, then x is rational"
The statement is true because the number x2 = π2 is irrational, therefore x = π is irrational.
Identify the component statements and the connective in the following compound statements.
It is raining or the sun is shining.
Identify the component statements and the connective in the following compound statements.
2 is a positive number or a negative number.
Translate the following statements in symbolic form
Tigers are found in Gir forest or Rajaji national park.
Rewrite the following statements in the form of conditional statements:
Mohan will be a good student if he studies hard.
Express in English, the statement p → q, where
p: It is raining today
q: 2 + 3 > 4
Translate the following statements in symbolic form:
If x = 7 and y = 4” then x + y = 11.
Translate the following biconditional into symbolic form:
“ABC is an equilateral triangle if and only if its each interior angle is 60°”
Check the validity of the statements:
s: 60 is a multiple of 3 or 5.
Which of the following sentences are statements? Justify
y + 9 = 7.
Find the component statements of the following compound statements.
The number 100 is divisible by 3, 11 and 5.
Write the component statements of the following compound statements and check whether the compound statement is true or false.
24 is a multiple of 4 and 6.
Write down the negation of following compound statements
A triangle has either 3-sides or 4-sides.
Write down the negation of following compound statements
All prime integers are either even or odd.
Form the biconditional statement p ↔ q, where
p: A natural number n is odd.
q: Natural number n is not divisible by 2.
Form the biconditional statement p ↔ q, where
p: A triangle is an equilateral triangle.
q: All three sides of a triangle are equal.
Identify the Quantifiers in the following statements.
For all real numbers x with x > 3, x 2 is greater than 9.
Identify the Quantifiers in the following statements.
There exists a even prime number other than 2.
Which of the following is not a statement>
The negation of the statement “Plants take in CO2 and give out O2 ” is ______.
Which of the following is not a negation of “A natural number is greater than zero”?
