Involving cos^-1(1+z/1-z)

Involving cos^-1(1+z/1-z) and cot^-1((-z)^1/2)

Involving cos^-1(1+z/1-z) and cot^-1(1/(-z)^1/2)

Involving cos^-1(1+z/1-z) and cot^-1((-1/z)^1/2)