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i x (a x i) + j x (a x j) + k x (a x k) = 2a

This type of question, asked 2 times: 2 May 2023 S2, 12 May 2026 S1. All 2 questions below, oldest first.

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  1. Question 1

    2 May 2023 S2

    138
    If a⃗=i^+2j^+3k^\vec{a} = \hat{i}+2\hat{j}+3\hat{k} and b⃗=i^×(a⃗×i^)+j^×(a⃗×j^)+k^×(a⃗×k^)\vec{b} = \hat{i}\times(\vec{a}\times\hat{i})+\hat{j}\times(\vec{a}\times\hat{j})+\hat{k}\times(\vec{a}\times\hat{k}), then ∣b⃗∣|\vec{b}| is

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  2. Question 2

    12 May 2026 S1

    90
    For any vector, aˉ\bar{a} if i^×(aˉ×i^)+j^×(aˉ×j^)+k^×(aˉ×k^)=maˉ\hat{i} \times (\bar{a} \times \hat{i}) + \hat{j} \times (\bar{a} \times \hat{j}) + \hat{k} \times (\bar{a} \times \hat{k}) = m\bar{a}, then the value of mm is ...

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