Let and . Which of the following equals…

MATHEMATICS · Single correct · CBSE · Mathematics · Vector Algebra · Vector Algebra

Problem

Let a=⟨a1,a2,a3⟩\mathbf{a}=\langle a_1, a_2, a_3\rangle and b=⟨b1,b2,b3⟩\mathbf{b}=\langle b_1, b_2, b_3\rangle. Which of the following equals a⋅b\mathbf{a}\cdot\mathbf{b}? (a) a12+b12+a22+b22+a32+b32a_1^2 + b_1^2 + a_2^2 + b_2^2 + a_3^2 + b_3^2 (b) a1b2+a2b3+a3b1a_1b_2 + a_2b_3 + a_3b_1 (c) a1b1+a2b2+a3b3a_1b_1 + a_2b_2 + a_3b_3 (d) (a1+b1)(a2+b2)(a3+b3)(a_1 + b_1)(a_2 + b_2)(a_3 + b_3)

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