Подстановка условия
[src]sin((n + 1)*x)/(2*(n + 1)) + sin((1 - n)*x)/(2*(1 - n)) при x = -1/3
sin((n + 1)*x)/(2*(n + 1)) + sin((1 - n)*x)/(2*(1 - n))
2(n+1)sin(x(n+1))+2(−n+1)sin(x(−n+1)) sin((n + 1)*(-1/3))/(2*(n + 1)) + sin((1 - n)*(-1/3))/(2*(1 - n))
2(n+1)sin((−1/3)(n+1))+2(−n+1)sin((−1/3)(−n+1)) sin((n + 1)*(-1)/3)/(2*(n + 1)) + sin((1 - n)*(-1)/3)/(2*(1 - n))
2(n+1)sin(31(−n−1))+2(−n+1)sin(31(n−1)) sin(-1/3 + n/3)/(2 - 2*n) - sin(1/3 + n/3)/(2 + 2*n)
−2n+2sin(3n+31)+−2n+2sin(3n−31)