KVPY2017MathematicsSets and Relations
Let S be the set of all ordered pairs (x, y) of positive integers satisfying the condition x²-y²=12345678 . Then
Options
- AS is an infinite set
- BS is the empty set
- CS has exactly one element
- DS is a finite set and has at least two elements.
Correct answer
B. S is the empty set
Step-by-step solution
x²-y²=12345678 (x, y I⁺ ) R.H.S. is even, so x , y should be odd integer but difference of square of two odd integers is multiple of 8 but R.H.S. is not multiple of 8