I have the given polar equation that I have to graph. r = 5/(-1 + 2 cos θ) The format is r = ed/(1 +e cosθ) (e and d are always positive) I can solve multiply r by -1/-1 --> r = -5/(1 - 2 cosθ). Is this possible? I thought that the numerator (ed) cannot be a negative number. Is this a misprint or is there a way to solve this?