IF a2+b2+c2=250 and ab+bc+ca=3, find a + b +c.
a2+b2+c2=250,ab+bc+ca=3(a+b+c)2=a2+b2+c2+2(ab+bc+ca)=250+2×3=250+6=256=(±16)2∴a+b+c=±16
Q2. if a2 +b2+c2=250 and ab+bc+ca=3 find a+b+c