Coefficients command is buggy
In current and beta versions of web-based Geogebra, the Coefficients command yields an error when fed a variable. For example:
yields the error "Illegal arguments: Number d" (clearly d isn't a number).
yields "Illegal argument: x".
This only is a problem on entry - any sheets I have created before using Coefficients continue to work as expected, but cannot be changed without producing one of the above errors.