Answer:
The answer in the procedure
Step-by-step explanation:
we know that
[tex]sin(A + B) = sin A cos B + cos A sin B[/tex]
In this problem we have
[tex]sin(x + \pi)=sin (x)cos(\pi) + cos(x)sin(\pi)[/tex]
Remember that
[tex]sin(\pi) = 0[/tex]
[tex]cos(\pi) = -1[/tex]
substitute
[tex]sin(x + \pi) = sin(x)(-1) + cos(x)(0)[/tex]
[tex]sin(x + \pi) = -sin(x)[/tex]
