Help with factoring out an exponential

*To*: mathgroup at smc.vnet.net*Subject*: [mg2304] Help with factoring out an exponential*From*: Rob Carscadden <carscadd at pps.pubpol.duke.edu>*Date*: Mon, 23 Oct 1995 12:42:58 -0400*Organization*: Duke University, Durham, NC, USA

I'm am trying to solve and equation but I can't factor out an exponential. I have an equation which will be given below, which has two exponentials: after taking the dervivatives I want to factor these out (throw them away really) so that mathematica has an algebraic equation to work with and I can find the critical points. Clearly these wil never be zero so I'm not losing anything. Here's my code where c is 5^x Print[eqn]; tempeqn = D[eqn,x]; test = Simplify[tempeqn/(Exp[-x^2/2])]; eqn1 = Simplify[test/c]; soln = Solve[eqn1 == 0,x]//N; Print[eqn1]; and here's my results: 2 x 0.75 0.09375 (1.5 + x) 5 (---------------- - ------------------) 2 2 x /2 x /2 E Sqrt[2 Pi] E Sqrt[2 Pi] x x x 2 x 3 (0.09375 (-3. 5 - 7.75 5 x + 3. 5 x + 1. 5 x x + 5.75 5 Log[5] - x x 2 x 3. 5 x Log[5] - 1. 5 x Log[5])) / (5 Sqrt[2 Pi]) As you can see every term in the numerator has an 5^x but it won't cancel with the denominator. Why? I'm goin gback to mathematica and try a change of base formula and see if this helps. Thanks for your help