( * )1 – (sin square y) / (1+cos y) + (1 + cos y) / ( sin y) – (sin y) /(1-cos y) =

Hello student, Please find the answer to your question below

1 – (sin square y) / (1+cos y) + (1 + cos y) / ( sin y) – (sin y) /(1-cos y)
= cos²y / (1 + cosy ) + (1 + cos y) / ( sin y) – (sin y) /(1-cos y)
if you take LCM of bold part and add it you will get numerator zero
so only first part will remian

=> cos²y / (1 + cosy )