1.
If a,b,c,da, b, c, d are distinct real numbers such that (a2+b2+c2)p22p(ab+bc+cd)+(b2+c2+d2)0(a^2+b^2+c^2)p^2 - 2p(ab+bc+cd) + (b^2+c^2+d^2) \le 0, then