Re: Simplification shortcomings?

*To*: mathgroup at smc.vnet.net*Subject*: [mg24653] Re: [mg24621] Simplification shortcomings?*From*: BobHanlon at aol.com*Date*: Mon, 31 Jul 2000 09:23:23 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Use FullSimplify In a message dated 7/28/2000 6:11:02 PM, nitlion at mindspring.com writes: >I'm a relative novice to Mathematica. While working with it today, I had >occasion to want to know if a result was equal to (1 + Sqrt[5])/2. The >result was shown as Sqrt[(3 + Sqrt[5])/2]. After some pancil and paper >work, I figured out that these two are equal. Or, I should say, that the >former is one of the values that the latter can have. > >I was frustrated in my attempts to get Mathematica to answer that question >for me. Simplify[(1 + Sqrt[5])/2 - Sqrt[(3 + Sqrt[5])/2]] didn't provide >any improvement. Calculating this value to many decimal digits showed >it >was near zero (probably close enough that I could have applied the >techniques shown in Scheinerman's recent article in American Mathematical >Monthly). The only way I got Mathematica to show the equality was to square >both numbers; Simplify[((1 + Sqrt[5])/2)^2 - (3 + Sqrt[5])/2] is zero. > >Is there any better way to do this? I have some other, more complicated >numbers that I need to compare. >