A symbol used to distinguish a third quantity 
("
double prime") from two other related quantities 
and 
("
prime). Double primes are most commonly
used to denote transformed coordinates, conjugate points, and derivatives.
A double prime is also used to denote the number of arc seconds in an angle measure,
or the number of inches in a length.
Double Prime
See also
PrimeExplore with Wolfram|Alpha
References
Bringhurst, R. The Elements of Typographic Style, 2nd ed. Point Roberts, WA: Hartley and Marks, p. 277, 1997.Referenced on Wolfram|Alpha
Double PrimeCite this as:
Weisstein, Eric W. "Double Prime." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/DoublePrime.html