Question

cos(X+Y) = 3÷5 and cos(X-Y) =
4
÷5
then sin 2X is equal to​

Answer 1

Answer:1

Step-by-step explanation:

Let, cos x + y =Cos A and cos x - y=cosB

So Cos A =3/5 and cosB=4/5

That means sin a =4/5 and Sin B =3 / 5

Now sin a + b =sin X + Y + x - Y =sin2x

We know that sin a + b =sin a cos b + cos a sin b

By substituting the values,

Sin a+ b =4/5(4/5)+3/5(3/5) =16/25 +9/25 =25/25=1

Therefore sin2x=1

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