Student Support Forum: 'Solving Log Equations' topicStudent Support Forum > General > "Solving Log Equations"

 < Previous Comment | Next Comment > Help | Reply To Comment | Reply To Topic
 Author Comment/Response yehuda ben-shimol 10/31/04 00:23am Hi, If you use simplification (as already given in previouse answers to your post) Simplify[2 Log[a, x] - Log[a, (x - 1)] == Log[a, (x - 2)]] you get (Log[-2 + x] + Log[-1 + x] - 2*Log[x])/Log[a] == 0 so the solution depends only on the numerator and involves only natural log (no "a" in the numerator) Plot the numerator and easily see that the numerator approaches the x axis from below (actually they meet at infinity). but forr all practical purposes a large enough number will do. for other cases where you may have a finite solution, after simplifying as mentioned befor, you may use numerical solution with FindRoot FindRoot["the numerator of the simplified expression",{x,x0}] where x0 is a starting value yehuda URL: ,

 Subject (listing for 'Solving Log Equations') Author Date Posted Solving Log Equations buffer 09/01/04 10:39pm Re: Solving Log Equations Andrew DuBui... 10/21/04 5:14pm Re: Solving Log Equations Paul Stysley 10/27/04 1:46pm Re: Solving Log Equations KENZOU 10/30/04 5:38pm Re: Solving Log Equations yehuda ben-s... 10/31/04 00:23am Re: Solving Log Equations Henry Lamb 10/31/04 11:52pm
 < Previous Comment | Next Comment > Help | Reply To Comment | Reply To Topic