olymmath

CR-MO 2013

Costa Rica national mathematics olympiad 2013.

Other problems

F1

Find all functions f:R→Rf: R\to R such that for all real numbers x,yx, y is satisfied that f(x+y)=(f(x))2013+f(y).f (x + y) = (f (x))^{ 2013} + f (y).

F2

Find all functions f:R−{0,2}→Rf:R -\{0,2\} \to R that satisfy for all x≠0,2x \ne 0,2 f(x)⋅(f(2+x2−x3))2=x34f(x) \cdot \left(f\left(\sqrt[3]{\frac{2+x}{2-x}}\right) \right)^2=\frac{x^3}{4}

G2

Consider the triangle ABCABC . Let P,QP, Q inside the angle AA such that ∠BAP=∠CAQ\angle BAP=\angle CAQ and PBQCPBQC is a parallelogram. Show that ∠ABP=∠ACP.\angle ABP=\angle ACP.

G3

Let ABCDABCD be a rectangle with center OO such that ∠DAC=60o\angle DAC = 60^o . Bisector of ∠DAC\angle DAC cuts a DCDC at SS , OSOS and ADAD intersect at LL , BLBL and ACAC intersect at MM . Prove that SM∥CLSM \parallel CL .

N1

Find all triples (a,b,p)(a, b, p) of positive integers, where pp is a prime number, such that ap−bp=2013a^p - b^p = 2013 .