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If acostheta+bsintheta=m and asintheta-b...

If `acostheta+bsintheta=m` and `asintheta-bcostheta=n ,` Prove that `a^2+b^2=m^2+n^2`

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Given : `acosθ+bsinθ=m ---( 1 )`
asinθ−bcosθ=n ---( 2 )
Squaring (1) and (2), we get
`a^2cos2θ+b^2sin2θ+2absinθcosθ=m^2 ---(3)` ...
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RD SHARMA-TRIGONOMETRIC IDENTITIES-All Questions
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  15. If tantheta+sintheta=m and tantheta-sintheta=n , then m^2-n^2=

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  20. If sectheta+tantheta=p , show that (p^2-1)/(p^2+1)=sintheta

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