MathDB

9

Part of 2011 Hanoi Open Mathematics Competitions

Problems(2)

1 + x + x^2 + x^3 + ... + x^{2011} = 0 (HOMC 2011 J Q9)

Source:

7/25/2019
Solve the equation 1+x+x2+x3+...+x2011=01 + x + x^2 + x^3 + ... + x^{2011} = 0.
algebraequation
function in N*xN*, f(x+1, y) = y[f(x, y)+f(x, y -1)], f(5, 5) (HOMC 2011 Q9)

Source:

7/25/2019
For every pair of positive integers (x,y)(x, y) we de fine f(x,y)f(x,y) as follows: f(x,1)=xf(x,1) = x f(x,y)=0f(x,y) = 0 if y>xy > x f(x+1,y)=y[f(x,y)+f(x,yāˆ’1)]f(x +1,y) = y[f(x,y)+ f(x, y-1)] Evaluate f(5,5)f(5, 5).
functiontwo variablespositive integers