The point at which a curve or function crosses the x-axis (i.e., when 
in two dimensions).
x-Intercept
See also
Line, y-InterceptExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "x-Intercept." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/x-Intercept.html