Re: Help needed in Mathematica
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: Help needed in Mathematica
- From: yoda at ele.crl.melco.co.jp (Kiyoshi Yoda)
- Date: Wed, 29 Jun 94 16:51:09 JST
>I've been unsucessfuly in converting from -4 Cos[t] - 4 Sin[t] to
>5.64 Cos[t + 3 Pi / 4].
>
>Handling transcedental functions is one of the weak parts of Mathematica.
>I appreciate any assistance on this problem.
What about this?
In[7]:=
trigrule=a_ Cos[t_] + b_ Sin[t_]->
Sqrt[a^2+b^2] Cos[t+ArcTan[a/b]];
In[8]:=
(-4 Cos[t] - 4 Sin[t]) /. trigrule
Out[8]=
Pi
4 Sqrt[2] Cos[-- + t]
4
Regards,
--
Kiyoshi Yoda yoda at ele.crl.melco.co.jp
Mitsubishi Electric Corp., Central Res. Lab.
8-1-1 Tsukaguchi Hommachi, Amagasaki 661 Japan