If A = Ax î + Ay ĵ + Az k̂ and B = Bx î + By ĵ + Bz k̂, which expression is correct?
Correct answer D. A · B = AxBx + AyBy + AzBz
Explanation
Because î·î = ĵ·ĵ = k̂·k̂ = 1 and the dot product of different unit vectors is zero, only matching components multiply, giving AxBx + AyBy + AzBz.
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