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Grade 12Trigonometry

If sinx+siny=a and cosx+cosy=2a what is the value of cos(x-y) ?

Profile image of Shushan
9 Years agoGrade 12
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1 Answer

Profile image of Bhumiti
9 Years ago
We know that cos(x-y) = cosx.cosy+sinx.siny... So just substitute the given values in the above equation... We get cos(x-y)=2a+a =3a