Re: Simple problem for math wiz

*To*: mathgroup at christensen.cybernetics.net*Subject*: [mg1708] Re: Simple problem for math wiz*From*: porfy at odin.gsfc.nasa.gov (Porfirio Beltran)*Date*: Wed, 19 Jul 1995 00:13:39 -0400*Organization*: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA

In article <DBKwIr.2qv at wri.com>, nomail at me.net (REVEAL) wrote: > Anyone here know how to find the solution set to: sin^2x+sinx-1=0 ? the trick, that is? > (limited to trig & algebra) Is this is the function you want to solve? In[1] Sin[x]^2 + Sin[x] - 1 == 0 Out[1] -1 + Sin[x] + Sin[x]^2 == 0 If so, I'm sure you know that the Mma Function 'Solve' doesn't cut it: In[2] Solve[Sin[x]^2 + Sin[x] - 1 == 0] Out[2] {{Sin[x] -> (-1 - 5^(1/2))/2},{Sin[x] -> (-1 + 5^(1/2))/2}} Use 'FindRoot': In[3] FindRoot[Sin[x]^2 + Sin[x] - 1 == 0, {x,0}] Out[3] {x -> YOU FIND IT!} Porfy. ** "Because is my nature..." - The Scorpion. **