Mathematica 7 does not know that Sin[2z] = 2 Sin[z] Cos[z]
in [Math]
|
Prev: Mathematica 7 vs Rubi: Tan[z]/Sqrt[1+Tan[z]^4]
Next: Galois Algebra Principle used to prove Goldbach Conjecture #686: Correcting Math
From: Vladimir Bondarenko on 16 Jul 2010 14:26 It calculates Integrate[1/(Sin[2 z]/2)^193, z] but returns Integrate[1/(Sin[z] Cos[z])^193, z] unevaluated. Cheers, Vladimir Bondarenko Co-founder, CEO, Mathematical Director http://www.cybertester.com/ Cyber Tester Ltd. ---------------------------------------------- "We must understand that technologies like these are the way of the future." ---------------------------------------------- ----------------------------------------------
From: Chip Eastham on 16 Jul 2010 14:35
On Jul 16, 2:26 pm, Vladimir Bondarenko <v...(a)cybertester.com> wrote: > It calculates > > Integrate[1/(Sin[2 z]/2)^193, z] > > but returns > > Integrate[1/(Sin[z] Cos[z])^193, z] > > unevaluated. > > Cheers, > > Vladimir Bondarenko > > Co-founder, CEO, Mathematical Director > > http://www.cybertester.com/ Cyber Tester Ltd. > > ---------------------------------------------- > > "We must understand that technologies > like these are the way of the future." > > ---------------------------------------------- > ---------------------------------------------- Judging by the results in Wolfram Alpha, it takes a wrong turn by expressing the second integrand in powers of secant and cosecant. However if you ask it to simplify/express sin(2x) - 2*sin(x)*cos(x), it gives 0 as the preferred result. regards, chip |