Question
Question: \(f:R \rightarrow Rf(x + y) = f(x) + f(y),\) ( [ ] denotes greatest integer function ) equal–...
f:R→Rf(x+y)=f(x)+f(y), ( [ ] denotes greatest integer function ) equal–
A
1
B
0
C
Does not exist
D
None of these
Answer
0
Explanation
Solution
(i) If x = Rational No. then 
. πx = Integer π
∴ cos (
. πx) = (–1 or 1)
cos2n (
πx) = + 1
(1 + cos2m (
πx)) = 1 + 1 = 2
(ii) If x Irrational No then n→∞h
πx= (Non Integer)π
(∴ – 1 < cos (
πx) < 1
⇒
(cos2m(
πx)) = 0 ∴ (less than 1)∞ = 0
⇒
(1 + cos2m
πx) =1 + 0 = 1
