Question

let a1,a2,a3,a4 be real number such that a1+a2+a3+a4=0 and a1^2+a2^2+a3^2+a4^2=1 then the smallest possible value of the expresion (a1-a2)^2+(a2-a3)^2+(a3-a4)^2+(a4-a1)^2 lies in which interval.

Answer 1

"Given that a2, a3, a4 ……a7 all are INTEGER

Condition is start from 0 (include) to j (but not include)

So for A2= 0 TO <2 SO ONLY possible values are A2= 0 ; 1

Same for others A3= 0 ; 1; 2;

A4= 0; 1; 2;3;

A5=0; 1; 2;3;4;

A6= 0; 1;2;3;4;5;

A7=0;1;2;3;4;5;6