Re: Need help with solving problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg5370] Re: [mg5339] Need help with solving problem*From*: Sherman Reed <Sherman.Reed at worldnet.att.net>*Date*: Thu, 5 Dec 1996 14:50:15 -0500*Sender*: owner-wri-mathgroup at wolfram.com

At 06:47 AM 11/27/96 +0000, you wrote: >Can anyone help me with this problem? > >(4^x)+(2^x)-2=0 > >Everyone can see that x=0 but: > >(4^x)+(2^x)-2=0 => >2*(2^x)+(2^x)-2=0 => THIS STEP IS NOT TRUE IT SHOULD BE 2*(2^(2*x-1))+(2^x)-2 >2y+y-2=0 => ;(let y=2^x) WHICH MAKES THE REST WRONG >3y=2 => TRY IT IN MMA >y=2/3 => >2^x=2/3 => ;(let 2^x=y) >lg(2^x)=lg(2/3) => >x*lg(2)=lg(2/3) => >x=lg(2/3)/lg(2) Which is not true!!! > >Am I doing something wrong? > >Please E-mail an answer to: >ingimar.volundarson at mailbox.swipnet.se > >Thanx in advance! > > >