Created attachment 108704 [details] Example file with data, fit and chart. The trendline equation of an exponential regression represented as follows: "f(x)=exp(-3608.77true0.09x)". It should read: "f(x)=exp(-3608.77)*exp(0.09x)".
*** Bug 85711 has been marked as a duplicate of this bug. ***
The string has been "f(x)=exp(-3608.77 + 0.09x)" in former versions and is now broken for some reason. Nevertheless, when fixing it, a change to your form would be good, because it is nearer to the usual y=a*e^{bx}.
There is no bug in Version: 4.3.6.2 Build ID: 430m0(Build:2) on Linux OpenSuse 13.2