8 Nov
2005
8 Nov
'05
9:21 a.m.
Hallo, Chuckk Hubbard hat gesagt: // Chuckk Hubbard wrote:
Now I'm seeing something. Ah ha. (cos x cos y) = (-cos x * cos y) = -(cos x cos y) and -(cos x cos y) + (sin x sin y) = -(cos(x+y)) = cos (x+y)
So the negative is a red herring since cosine is an even function? (I use x and y not as polar terms, but because I have no theta key)
Crazy. I wonder if that's right.
It's not right, because: cos(x) != -cos(x). You probably intended to use cos(x) == cos(-x), but that's different thing.
Ciao
Frank Barknecht _ ______footils.org_ __goto10.org__