Hello!

I've got the following problem:

Find the solution to the following IVP:

v_y(x,y)+cv_x(x,y)=u(x,y) satisfying v(x,0)=v_0(x)

where v_0\in C^1(\mathbb{R}), u\in C^1(\mathbb{R}^2) and the constant c\in \mathbb{R}.
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I tried to diff. once in x and once in y but couldn't see how that would help.