50g

I'm glad to be a new member. 

I am a new owner of a 50g since Nov.2006. I'm slowly learning to use 
this calculator.

I can't get the the equation Ke = -Ln[(Vd)(Tr)divided by D divided by 1+
(Vd)(Tr)] divided by tau minus t'. I'm using the algabraic mode. I use 
this equation at work. I know the numerical values for variables except 
Ke. It would be very helpful to store this equation and plug in the 
variables.

I have spent hours on this equation , but still get the "syntex error"  
message.

I would appreciate any help.

Bob Blackwelder

Knoxville, Tennessee