Prove that (10) 3 is an irrational number.
Answers
Step-by-step explanation:
Atmospheric pressure, also known as barometric pressure, is the pressure within the atmosphere of Earth. The standard atmosphere is a unit of pressure defined as 101,325 Pa, which is equivalent to 760 mm Hg, 29.9212
Answer:
Question :
Prove that sqaure root of 3 is an irrational number.
Solution :
Let us assume to the contrary that √3 is a rational number.
It can be expressed in the form of p/q
It can be expressed in the form of p/qwhere p and q are co-primes and q≠ 0.
⇒ √3 = p/q
⇒ 3 = p^2/q^2 (Squaring on both the sides)
⇒ 3q^2 = p^2 ------------------------(1)
It means that 3 divides p^2 and also 3 divides p because each factor should appear two times for the square to exist.
So we have p = 3r
where r is some integer.
⇒ p^2 = 9r^2 -----------------------(2)
from equation (1) and (2)
⇒ 3q^2 = 9r^2
⇒ q^2 = 3r^2
We have two cases to consider now.
Case I
Suppose that r is even. Then r^2 is even, and 3r^2 is even which implies that q^2 is even and so q is even, but this cannot happen. If both q and r are even then gcd(q,r)≥2 which is a contradiction.
Case II
Now suppose that r is odd. Then r^2 is odd and 3r^2 is odd which implies that q^2 is odd and so q is odd. Since both q and r are odd, we can write q=2m−1 and r=2n−1 for some m,n∈N.
Therefore
q^2=3r^2
(2m−1)2=3(2n−1)^2
4m^2−4m+1=3(4n2−4n+1)
4m^2−4m+1=12n^2−12n+3
4m^2−4m=12n^2−12n+2
2m^2−2m=6n^2−6n+1
2(m^2−m)=2(3n^2−3n)+1
We note that the lefthand side of this equation is even, while the righthand side of this equation is odd, which is a contradiction. Therefore there exists no rational number r such that r^2=3.
Hence the root of 3 is an irrational number.