If f(n)=a^n+b^n+c^n   and f(1)=1,f(2)=2,f(3)=3 ,n=1,2,3,.... Find f(5) ?

Let a,b and c be the three roots of the equation :2012x^3+2013x+2014=0.Find (a+b)^3+(b+c)^3+(c+a)^3?

Find a(n)of sequence:5, 7, 7, 2, 1, 5, 6, 6, 4, ...............

Find a(n)of sequence1,8,1,4,7,0,7,0,....   (n=1,2,3,4,...) ,

Given the pencil of lines a(3x+4y-10)+b(3x-y-5)=0.Find pencil of lines is tangent to the circle x^2+y^2+2x-4y=0?