Involving cos-1((z+a)1/2/z1/2)
Involving cos-1((z-1)1/2/z1/2) and sech-1(z1/2)
Involving cos-1((z+1)1/2/z1/2) and sech-1(z/z+2)
Involving cos-1((z+1)1/2/z1/2) and sech-1(z/z+11/2)