I think there is a bug in CAS mode using "zeros", "solve"

[John P]

I think there is a bug in CAS mode using "zeros", "solve". I have fn: "-e^x*(-cos(x)+sin(x))" and I need zeros of that fn. I use zeros(-e^x*(-cos(x)+sin(x)),x) and I get the error: "Unable to isolate x in cos(x)-sin(x)" but when I use zeros(e^x*(-cos(x)+sin(x)),x) I get the zeros [1/4*Pi,5/4*Pi] and no error. What I've done I changed the minus sign in front of e to plus sign and there is no error. It looks like the "-" in front of "e" makes all the difference. On plot both functions have the same zeros. Using "solve" does the same thing.