# Math Help - Simple Trig Identities

1. ## Simple Trig Identities

I have this following part of a question: ....... where sin x cannot be 0.

Does that mean in my calculations i can not deal with sin x? or what ? because i don't really understand since i am not dealing with numbers to begin with.

2. ## Re: Simple Trig Identities

$\sin{x} \ne 0$ is stating a domain restriction for $x$ ... $x \ne k \pi \, , \, k \in \mathbb{Z}$