I'm having massive difficulty in rearranging the following to find d
taking the natural log of both sides normally helps when there is an exp function present but here it just gets in the way - no matter how hard I try I can't get d on its own (d in terms of c and r).
can anyone help?
showing the steps you took would help me tackle similar problems in the future so I'd be extremely grateful for this.
Massive thanks in advance.