sin(π-x)+sin(π+x)-cos(-x)+cos(2π-x)-tan(π+x)cot(π-x)
=-sin(-x)-sin（x）-cos(x)+cos(-x)-[-tan(x)][-cot(-x)]
=sin(x)-sin(x)-cos(x)+cos(x)-tan(x)cot(-x)
=-tan(x)cot(-x)
=-tan(x)[-cot(x)]
=1