Which of the following is equivalent to sin(x)+sin(y)cos(x)+cos(y)\frac{\sin(x) + \sin(y)}{\cos(x) + \cos(y)}cos(x)+cos(y)sin(x)+sin(y)?
tan((x+y)/2)\tan((x+y)/2)tan((x+y)/2)
tan((x−y)/2)\tan((x-y)/2)tan((x−y)/2)
cot((x+y)/2)\cot((x+y)/2)cot((x+y)/2)
sin((x+y)/2)\sin((x+y)/2)sin((x+y)/2)