Find the potential \( \phi(\mathbf{x}, y) \) of an electrostatic field \( \mathbf{E}=a(y \mathbf...

Find the potential \( \phi(\mathbf{x}, y) \) of an electrostatic field \( \mathbf{E}=a(y \mathbf{i}+x \mathbf{j}) \), where \( a \) is a constant, \( \mathbf{i} \) and \( \mathbf{j} \) are the unit vectors of the \( x \) and \( y \) axes.