Involving csc-1(21/2/(1-(1+c z2)1/2)1/2)
Involving csc-1(21/2/(1-(1+z2)1/2)1/2) and sech-1(-i/z)
Involving csc-1(21/2/(1-(1- z2)1/2)1/2) and sech-1(1/z)