The following markup provides the correct result, except that it is too long for one line (and could be much longer):

T(x) = sqrt { [0.0005 - 0.00106 x + 0.001 x^2 + 0.00141 x^3]^2 - [0.000866 + 0.00106 x + 0.000707 x^2 + 0.00141 x^3]^2 }

However, inserting “newline” breaks it:

T(x) = sqrt {[0.0005 - 0.00106 x + 0.001 x^2 + 0.00141 x^3]^2 newline - [0.000866 + 0.00106 x + 0.000707 x^2 + 0.00141 x^3]^2}

How can I display the “contents” of a sqrt symbol over multiple lines? Preferably this would involve a scaled (enlarged) sqrt symbol, but would be acceptable if the symbol’s overhead line extended over more than one line.

The root of the issue seems to be that Math doesn’t like brackets or braces that contain newline - brackets seem to need to be on the same line. So there is a conflict between the need to contain the “contents” of the sqrt symbol within braces or brackets and the need the spread these “contents” over multiple lines.

LibreOffice Version: 4.2.7.2, Ubuntu 14.04 LTS 64