prove that sin a + b into Sin A minus b equal to sin square A minus sin square B
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Answered by
22
Step-by-step explanation:
Sin(a+b) * Sin(a-b)
(Sina*Cosb+Cosa*Sinb)(Sina*Cosb-Cosa*Sinb)
(Sina*Cosb)² - (Cosa*Sinb)²
Sin²a * Cos²b - Cos²a * Sin²b
Sin²a(1-Sin²b) - Cos²a*Sin²b
Sin²a - Sin²a*Sin²b - Cos²a*Sin²b
Sin²a - Sin²b(Sin²a + Cos²a)
Sin²a - Sin²b(1)
Sin²a - Sin²b
Answered by
7
\sin^2A\cos^2B-\cos^2A\sin^2B=\sin^2A-\sin^2B proved.
Step-by-step explanation:
Consider the provided information.
\sin^2A\cos^2B-\cos^2A\sin^2B=\sin^2A-\sin^2B
Consider the LHS.
\sin^2A\cos^2B-\cos^2A\sin^2B
\sin^2A(1-\sin^2B)-(1-\sin^2A)\sin^2B (∴\cos^2x=1-\sin^2x)
\sin^2A-\sin^2A\sin^2B-\sin^2B+\sin^2A\sin^2B
\sin^2A-\sin^2B
Hence, proved.
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