Involving cos-1((c z)1/2)
Involving cos-1(z1/2) and cosh-1(z1/2)
Involving cos-1(z1/2) and cosh-1(1/1/z1/2)
Involving cos-1((-z)1/2) and cosh-1((1+z)1/2)
Involving cos-1((-z)1/2) and cosh-1(1+2 z)