Hi,
We can find a function fun for a triangle such that:
* fun(x,y) = 0 if (x,y) lies on the triangle, i.e., fun(x,y) = 0 is an equation for the triangle;
* fun(x,y) < 0 if (x,y) lies inside the triangle;
* fun(x,y) > 0 if (x,y) lies outside the triangle.
The function for the triangle...
Hint
Consider the intersection of a horizontal plane with the surface.
The intersection consists of a family of funny curves.
(An example curve is shown below. It has nothing to do with the answer.)
Cut off the upper surface above the horizontal plane to get a funny 3D image.
(This...
The surface in above image is a portion of the graph of
some mathematical equation.
Let's do some brainstorming:
Can you guess what's inside the surface?
.
.