Involving sin-1((a-z2)1/2/(-z2)1/2)
Involving sin-1((1-z2)1/2/(-z2)1/2) and cosh-1(1/z)
Involving sin-1((-1-z2)1/2/(-z2)1/2) and cosh-1(z2+2/z2)
Involving sin-1((-1-z2)1/2/(-z2)1/2) and cosh-1((1+1/z2)1/2)