Find dy/dx when y=0 if xcosy-sinx-2=0

xcos (y) - - > For this part, use the product rule, which would mean

cosy - xsiny * dy/dx

sinx's derivative is just cosx, so we get as a final answer

cosy - xsiny * dy/dx - cosx = 0

-xsiny * dy/dx = cosx - cosy

dy/dx = cosx - cosy / - xsiny

When y=0,

dy/dx = cosx - cosy / - xsiny

dy/dx = cosx - cos (0) / - xsin (0) [note: sin (0) = 0]

dy/dx = undefined [since you can't divide by 0]