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