It only matters what is the angle between the lines tangent to the curves at the point of intersection. Here's an example: https://www.desmos.com/calculator/is

It only matters what is the angle between the lines tangent to the curves at the point of intersection. Here's an example: https://www.desmos.com/calculator/is7mush1ma https://www.desmos.com/calculator/is7mush1ma The red and blue circles are both perpendicular to the green circle at the origin.