Question

cos (x+y)=cos xcosy -sinxsiny ,B)cos(x-y)=cosxsiny +sinxsiny C)sin(x+y)=sinxcosy +cosx +siny .Find the correct option a)A and B true b)A and C true c)A,B and c True​

Answer 1

Answer:

I think

B)A and C true

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