MENU
Question -

Prove that if x and y are both odd positiveintegers, then x2┬а+ y2┬аis even but notdivisible by 4.



Answer -

Solution:

Let the two odd positive numbers x and y be 2k+ 1 and 2p + 1, respectively

i.e., x2┬а+ y2┬а=(2k + 1)2┬а+(2p + 1)2

= 4k2┬а+ 4k + 1 + 4p2┬а+4p + 1

= 4k2┬а+ 4p2┬а+4k + 4p + 2

= 4 (k2┬а+ p2┬а+k + p) + 2

Thus, the sum of square is even the number isnot divisible by 4

Therefore, if x and y are odd positiveinteger, then x2┬а+ y2┬аis even but not divisibleby four.

Hence Proved

Comment(S)

Show all Coment

Leave a Comment

Free - Previous Years Question Papers
Any questions? Ask us!
×