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Prove that vectors (a + b).(a - b) = |a|2 + |b|2 ⇔ a⊥b, where vectors a ≠ 0 and vectors b ≠ 0. |
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Answer» \((\vec{a}+\vec{b}).(\vec{a}-\vec{b})\) = \(|\vec{a}|^2+|\vec{b}|^2\) ⇒ \(|\vec{a}|^2-|\vec{b}|^2\) = \(|\vec{a}|^2+|\vec{b}|^2\) ⇒ \(|\vec{b}|\) = 0 Which is not possible hence \((\vec{a})⊥(\vec{b})\) |
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