Q27 of 25 Page 3

If and prove that



Proof:


We know,


sin2 α + cos2 α = 1


⇒ cos2 α = 1 – sin2 α







Similarly,


sin2 β + cos2 β = 1


⇒ sin2 β = 1 – cos2 β







Identity used:


cos (α – β) = cos α cos β + sin α sin β










Hence Proved

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