Question 595825
sin(x-y)cos(y)+cos(x-y)sin(y)


sin( (x-y) + y) ... See <font color="red">note</font> below


sin(x - y + y)


sin(x)



Answer: So <img src="http://latex.codecogs.com/gif.latex?\Large \sin(x-y)\cos(y)+\cos(x-y)\sin(y) = \sin(x)" title="x" /> for all values of x and y.


<font color="red">Note</font>: In step 2, I used the identity sin(A + B) = sin(A)cos(B)+cos(A)sin(B)