A student was asked to prove the trigonometric identity

Last updated: 8/4/2022

A student was asked to prove the trigonometric identity tan1/2x + cot1/2x = 2cscx. Which of the following could be the first step in proving the identity? I. 1-cosx/sinx + 1-cosx/sinx = 2cscx II. 1+cosx/sinx + sinx/1-cosx = 2cscx III. sinx/ 1+cosx + 1+cosx/sinx = 2cscx