C-03-Q042mediumsingle_mcqIf a+b+c=2a+b+c=2a+b+c=2 and ab+bc+ca=1ab+bc+ca=1ab+bc+ca=1, (a+b)2+(b+c)2+(c+a)2=?(a+b)^2+(b+c)^2+(c+a)^2 = ?(a+b)2+(b+c)2+(c+a)2=?a444b666c888d101010ব্যাখ্যাThe expression expands to 2(a2+b2+c2)+2(ab+bc+ca)2(a^2+b^2+c^2)+2(ab+bc+ca)2(a2+b2+c2)+2(ab+bc+ca). Since a2+b2+c2=(a+b+c)2−2(ab+bc+ca)=4−2=2a^2+b^2+c^2=(a+b+c)^2-2(ab+bc+ca)=4-2=2a2+b2+c2=(a+b+c)2−2(ab+bc+ca)=4−2=2, the value is 2(2)+2(1)=62(2)+2(1)=62(2)+2(1)=6.