1. The problem statement, all variables and given/known data d/dx 1/sin(y/2) 3. The attempt at a solution this isn't an entire question, just looking for clarification about something. i have been asked as part of a larger question to find the partial derivative of 1/sin(y) with respect to x. in this case you treat y as a constant, yes? so d/dx of (sin(y/2) = cos(y/2)*dy/dx, since y is treated as a constant, dy/dx = 0, so d/dx of sin(y/2) = 0. if you use the quotient rule on the full equation, you divide by 0^2, which is 0, so you end up dividing by 0. Is this correct? The full expression actually has sin(x/2 + y/2) above instead of 1. is it just a matter of rearranging this expression so that the bottom cancels out? or does d/dx sin(y/2) not actually evaluate to 0 in the first place? thanks in advance!