If one line of the equation :
ax^3 +bx^2 y+cxy^2 +dy^3 =0
bisects the angle between the
the other two then prove
(3a+c)^2 (bc+2cd−3ad)=
(b+3d)^2 (bc+2ab−3ad) .
1) find P∈R[x] / P(sinx) =sin(2n+1)x
2) find the roots of P and degP
3) decompose (1/P) and prove that
((2n+1)/(sin(2n+1)x)) = Σ_(k=0) ^(2n) (((−1)^k cos(((kπ)/(2n+1))))/(sinx−sin (((kπ)/(2n+1)))))) .