Question

a^3+b^3+c^3=12,abc=4,ab+bc+ca=5,find a^2+b^2+c^2,a+b+c=4

Answer 1

Answer:

a^3+b^3+c^3-3abc=12-4*3=0

a^3+b^3+c^3-3abc=(a+b+c)(a^2+b^2+c^2-ab-bc-ac)

0=4*(a^2+b^2+c^2-(5)

0/4=a^2+b^2+c^3-5

a^2+b^2+c^2=0+5=5ans.