Dear Friends,

I've got 2 exercises I can't solve.

The first one is :

If a,b,c ∈ C and they are affix points of the plan.

Show that the triangle ABC is equilateral only if

a^2+b^2+c^2 = ab+ bc + ca

The second one is to demonstrate that :

X^4 + 2X^3 + 4X^2 + 2X + 3

has no square root in R.

I'm looking forward to your answers,

Many Thanks,

Fred

PS : Sorry for my bad english