derivative of inverse tangent

Let us solve problem on derivative of inverse tangent

-->Derivative of inverse tangent angle when z =sixty.

Angle = arctan z

Angle = arctan sixty

Angle = 1.554131203081 radian

In degree mode 89.045158746128

Derivative of inverse tangent angle when z=90.

Angle = arctan z

Angle = arctan ninety

Angle = 1.5596856728973 radian

In degree mode = 89.363406424037.