Use Euclid’s division lemma to show that the square of any positive
integer is either of form 3m or 3m + 1 for some integer m.
[Hint: Let x be any positive integer then it is of the form 3q, 3q + 1 or
3q + 2. Now square each of these and show that they can be rewritten
in the form 3m or 3m + 1.]
Answers
Answer:
Let take a as any positive integer and b = 3.
Then using Euclid’s algorithm we get a = 3q + r here r is remainder and value of q is more than or equal to 0 and r = 0, 1, 2 because 0 < r < b and the value of b is 3 So our possible values will 3q+0 , 3q+1 and 3q+2
Now find the square of values
Use the formula (a+b)² = a² + 2ab +b² to open the square bracket
(3q)² = 9q² if we divide by 3 we get no remainder
we can write it as 3*(3q²) so it is in form of 3m here m = 3q²
(3q+1)² = (3q)² + 2*3q*1 + 1²
=9q² + 6q +1 now divide by 3 we get 1 remainder
so we can write it as 3(3q² + 2q) +1 so we can write it in form of 3m+1 and value of m is 3q² + 2q here
(3q+2)² = (3q)² + 2*3q*2 + 2²
=9q² + 12q +4 now divide by 3 we get 1 remainder
so we can write it as 3(3q² + 4q +1) +1 so we can write it in form of 3m +1 and value of m will 3q² + 4q +1
Square of any positive integer is either of the form 3m or 3m + 1 for some integer
This might be the answer.
Answer:
My frnd, Euclids division lemma is cancelled for the year 2020-21