The integrals below involve `coth ax`.
1) `int coth ax dx = 1/a ln sinh ax`
2) `int coth^2 ax dx = x-(coth ax)/a`
3) `int coth^3 ax dx = 1/a ln sinh ax-(coth^2 ax)/(2a)`
4) `int coth^n ax*\text{csch}\^2 ax dx = -(coth^(n+1) ax)/((n+1)a)`
5) `int (\text{csch}\^2 ax)/(coth ax) dx = -1/a ln coth ax`
6) `int 1/(coth ax) dx = 1/a ln cosh ax`
7) `int x coth ax dx = 1/a^2{ax+(ax)^3/9-(ax)^5/225+...((-1)^(n-1)2^(2n)B_n(ax)^(2n+1))/((2n+1)!)+...}`
8) `int x coth^2 ax dx = x^2/2-(x coth ax)/a+1/a^2 ln sinh ax`
9) `int (coth ax)/x dx = -1/(ax)+(ax)/3-(ax)^3/135+...((-1)^n2^(2n)B_n(ax)^(2n-1))/((2n-1)(2n)!)+...`
10) `int 1/(p+q coth ax) dx = (px)/(p^2-q^2)-q/(a(p^2-q^2)) ln (p sinh ax+q cosh ax)`
11) `int coth^n ax dx = -(coth^(n-1)ax)/(a(n-1))+ int coth^(n-2) ax dx`