which is the same as 2(x+ 1)+ y= 1

which is the same as 2(x+1)+ y= 1 again.1/(y+2(x+1)) -1=0

This last equation is incorrect. It should be either y= -(2x+1) or y= -2x- 1.as result I get x=-(y+1)/2 and y=(-2x+1)

On the contrary, the two equations are equivalent so thatI can find no points, for which this holds... Did I do some mistake in my calculations or can I say that for this function I have no stationary points?everypoint on the line y= -2x- 1 is a stationary point.