For any integer n, let I_n be the interval (n, n+1).
Define
R={(x, y)∈R∣both x, y ∈ I_n for some n∈Z}
Then R is
(A) reflexive on R
(B) symmetric
(C) transitive
(D) an equivalence relation
Q1
If f:R→R is defined by
f(x)=[x]+[x+(1/2)]+[x+(2/3)]−3x+5
where [x] is the integral part of x, then a period of f is
(A) 1 (B) 2/3 (C) 1/2 (D) 1/3
Q2
Let a<c<b such that c−a=b−c. If f:R→R is a
function satisfying the relation
f(x+a)+f(x+b)=f(x+c) for all x∈R
then a period of f is
(A) (b−a) (B) 2(b−a)
(C) 3(b−a) (D) 4(b−a)
Given k ∈ N.
1) justify these relations:
3^(2k) +1≡2[8] and 3^(2k+1) +1≡4[8].
2) Given (E): 2^n −3^m =1. n and m are unknowed.
• Show that if m is even , (E) does not have
solution.
■ Deduct from the first question 1) that the
couple (2;1) is the only solution of (E).
Let a<c<b such that c−a=b−c. If f:R→R is a
function satisfying the relation
f(x+a)+f(x+b)=f(x+c) for all x∈R
then a period of f is
(A) (b−a) (B) 2(b−a)
(C) 3(b−a) (D) 4(b−a)
Let a>0 and f:R→R a function satisfying
f(x+a)=1+[2−3f(x)+3f(x)^2 −f(x)^3 ]^(1/3)
for all x∈R. Then a period of f(x) is ka where k is
a positive integer whose value is
(A)1 (B)2 (C)3 (D)4