Question

sa se arate ca daca a,b,c€R,atunci:a^2+b^2+c^2+ab+bc+ca=1/2[(a+b)^2+(b+c)^2+(c+a)^2]

Answer 1

M2=(a^2+2ab+b^2+b^2+2bc+c^2+c^2+2ac+a^2) / 2 =
= 2(a^2+b^2+c^2+ab+bc+ca) / 2 = M1

Q.E.D. Qvot Eram Demonstrandum-lat.

Succes in continuare! Si astept coronita!