Question

cosec 0degree=_____​

Answer 1

undefined

cosec(0) = 1/sin(0) by definition.

sin(0) = 0

Therefore cosec(0) evaluates to 1/0, which is an indeterminate form.

Conclusion: the cosecant function is undefined at 0.

If you want proof that sin(0) is 0, just draw out the right triangle in question, or equivalently, look at this location on the unit circle.