plot_real_imag(sqrt(x), (x, -3, 3), real=False, imag=False, abs=True, arg=True)
# Expected:
## Plot object containing:
## [0]: cartesian line: sqrt(sqrt(re(x)**2 + im(x)**2)*sin(atan2(im(x), re(x))/2)**2 + sqrt(re(x)**2 + im(x)**2)*cos(atan2(im(x), re(x))/2)**2) for x over (-3.0, 3.0)
## [1]: cartesian line: arg(sqrt(x)) for x over (-3.0, 3.0)