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Question
Without expanding, show that Δ = `|("cosec"^2theta, cot^2theta, 1),(cot^2theta, "cosec"^2theta, -1),(42, 40, 2)|` = 0
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Solution
Applying C1 → C1 – C2 – C3, we have
Δ = `|("cosec"^2theta - cot^2theta - 1, cot^2theta, 1),(cot^2theta - "cosec"^2theta + 1, "cosec"^2theta, -1),(0, 40, 2)|`
= `|(0, cot^2theta, 1),(0, "cosec"^2theta, -1),(0, 40, 2)|`
= 0
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