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MathsMediumMCQ2021 · 16 Mar Shift 1

Q61.If for x ∈(0, π2 ), log10 sin x + log10 cos x = −1 and log10(sin x + cos x) = 12 (log10 n −1), n > 0 , then the value of n is equal to : (1) 20 (2) 12 (3) 9 (4) 16

What This Question Tests

This question combines logarithmic properties with trigonometric identities to solve a system of equations, ultimately finding the value of an unknown constant.

Concepts Tested

Properties of logarithmsTrigonometric identitiesSolving equations

Formulas Used

log a + log b = log (ab)

log aⁿ = n log a

sin²x + cos²x = 1

(sin x + cos x)² = 1 + 2 sin x cos x

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