There are infinite black and white dots on a plane. Prove that the distance between one black dot and one white dot is one unit.

Assumption is false

Explanation:

You don't prove, because it's false. If all black dots happen to be on the line and white dots on the line (and the rest of the plane is neither white nor black), there is no such pair.

this is confusing and what subject is this

Explanation:

answer:

a possibility is  vasodilation.

"sweat  secretion stops when body temperature returns to normal. blood vessels supplying blood to the skin can swell or dilate - called  vasodilation."

"to maintain homeostasis, the blood vessels in your skin dilate to allow more blood flow to the surface of your body where it disperses the heat. you won’t feel the vasodilation, but you certainly will feel yourself sweating."

explanation: