Consider a 3 × 3 real symmetric matrix S such that two of its eigenvalues are a ≠ 0, b ≠ 0 with respective eigen vectors \(\left[ {\begin{array}{*{20}{c}} {{x_1}}\\ {{x_2}}\\ {{x_3}} \end{array}} \right],\left[ {\begin{array}{*{20}{c}} {{y_1}}\\ {{y_2}}\\ {{y_3}} \end{array}} \right]\).If a ≠ b then x1y1 + x2y2 + x3y3 equals

Consider a 3 × 3 real symmetric matrix S such that two of its eigenva

1.	Consider a 3 × 3 real symmetric matrix S such that two of its eigenvalues are a ≠ 0, b ≠ 0 with respective eigen vectors \(\left[ {\begin{array}{{20}{c}} {{x_1}}\\ {{x_2}}\\ {{x_3}} \end{array}} \right],\left[ {\begin{array}{{20}{c}} {{y_1}}\\ {{y_2}}\\ {{y_3}} \end{array}} \right]\).If a ≠ b then x1y1 + x2y2 + x3y3 equals
A.	a
B.	b
C.	ab
D.	0
Answer» E.