This is the value of the dot product of two perpendicular vectors, and this number is the additive identity.
This is the value of a closed path integral of work in a conservative vector field. The only function whose domain is the reals and that is both even and odd only gives this number as an output. This number is used in the name of a game in which the total gains equal the total losses. If the product of two numbers equals this number, then one of those numbers equals this number. This is the value of the dot product of two perpendicular vectors, and this number is the additive identity. Name this real number that is neither positive nor negative.
This is the value of a closed path integral of work in a conservative vector field.
zero (or equivalents)