A function 
of one or more variables whose range is one-dimensional,
as compared to a vector function, whose range
is three-dimensional (or, in general, 
-dimensional).
Scalar Function
See also
Complex Function, Real Function, Vector FunctionExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Scalar Function." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ScalarFunction.html