If c o s B c o s A = n , s i n B s i n A = m , then the value of ( m 2 − n 2 ) sin 2 B is

cos A = n cos B and sin A = m sin B Squaring and adding, we get 1 = n 2 cos 2 B + m 2 sin 2 B ⇒ ∴ 1 = n 2 ( 1 − sin 2 B ) + m 2 sin 2 B ( m 2 − n 2 ) sin 2 B = 1 − n 2

Mathematics - Trigonometric Ratios & Identities Question with Solution | TestHub

MathematicsTrigonometric Ratios & IdentitiesBasic Identities & T RatiosEasy2 minPYQ_2015

MathematicsEasysingle choice

If $\frac{c o s A}{c o s B} = n, \frac{s i n A}{s i n B} = m$ , then the value of $(m^{2} - n^{2}) sin^{2} B$ is

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$cos A = n cos B$ and $sin A = m sin B$ Squaring and adding, we get $1 = n^{2} cos^{2} B + m^{2} sin^{2} B$ $\Rightarrow ∴ 1 = n^{2} (1 - sin^{2} B) + m^{2} sin^{2} B (m^{2} - n^{2}) sin^{2} B = 1 - n^{2}$

Stream:BITSATSubject:MathematicsTopic:Trigonometric Ratios & IdentitiesSubtopic:Basic Identities & T Ratios

⏱ 2mℹ️ Source: PYQ_2015

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