The solution
where is the Riemann function of the linear Goursat problem with characteristics according to the Riemann method.
The solution
where is the Riemann function of the linear Goursat problem with characteristics according to the Riemann method.
Weisstein, Eric W. "Riemann Formula." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RiemannFormula.html