The expression (sin7y cos 3y-cos 7y sin 3y) as the sine or cosine of an angle is given as cos(10y)
This is further explained below.
<h3>What are the identities of trigonometric functions?</h3>
"Equalities that utilize trigonometry functions and are true no matter what the values of the variables that are supplied in the equation are what are referred to as trigonometric identities.
There are many other trigonometric identities that may be found using the length of a triangle's side as well as the angle of the triangle."
In conclusion, From the trigonometric identities derivatives, we know that
cos(A + B) = cos(A) cos(B) - sin(A) sin(B)
Hence, when we implore said identity in the expression
(sin7y cos 3y-cos 7y sin 3y)
We have
= cos(7y + 3y)
= cos(10y)
Read more about trigonometric identities.
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