Can somebody please help as soon as possible with this? I need the step by step answer...thanks
Answers
Answer:
Hii Mate ^_^
1) √3 is irrational
Proof :
Let us assume that √3 is a rational number.
Then, as we know a rational number should be in the form of p/q,
where p and q are co- prime number.
So,
√3 = p/q { where p and q are co- prime}
√3q = p
Now, by squaring both the side
we get,
(√3q)² = p²
3q² = p² ........ ( i )
So,
If 3 is the factor of p²,
then, 3 is also a factor of p ..... ( ii )
=> Let p = 3m { where m is any integer }
Squaring both sides
p² = (3m)²
p² = 9m²
Putting the value of p² in equation ( i )
3q² = p²
3q² = 9m²
q² = 3m²
So,
If 3 is factor of q²,
then, 3 is also factor of q.
Since,
3 is a factor of p & q both,
So, our assumption that p & q are co- prime is wrong
Hence,
√3 is an irrational number
2) 7+2√3 is irrational
Proof :
Let, if possible, 7 + 2 under root 3 be a rational no.
This will give rise to 2 unique integers a and b such that,
7+2 under root 3, where a and b are co primes and b is not equal to 0.
Now,
7+2√3 = a/b
2√3= (a/b)-7
√3 = (a/2b)-(7/2)
Here, as a , b , 7 and 2 are all integers, (a/2b)-(7/2) is real.
This implies that √3 is also a rational no.
However, we have just proved above that √3 is an irrational no.
So, This is a contradiction.
Therefore, our assumption was wrong.
Hence,
7+2 under root 3 is an irrational no.