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Are these correct derivatives?
Just add pi over 2 in radians?
Seems to be right to me, even though we usually don't see the derivatives with a phase shift, but usually flip between sine and plus or minus cosine.
Last edited by John E. Franklin (2007-02-24 07:48:27)
igloo myrtilles fourmis
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Yeah!! I was thinking about the unit circle, how I was taught trig in high school,
and trying to visualize stuff. It's pretty exciting!!
igloo myrtilles fourmis
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Also
Cos[sup](n)[/sup](x)=Cos(x+nπ/2)
Sin[sup](n)[/sup](x)=Sin(x+nπ/2)
where (n) stands for the nth derivative.
X'(y-Xβ)=0
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That's neat! George. So the 4th and 8th derivatives just come back to where you started.
igloo myrtilles fourmis
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yes, you can see the same thing when just dealing with the derivitaves normally.
The Beginning Of All Things To End.
The End Of All Things To Come.
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Interesting lucadd. It's funny how I memorize them.
It's hard to explain, but when they all stay cosine, then you go
counter-clockwise a quarter turn. But if you change from
sin to cos to - sin to - cos to sin and around, you can remember
vectors pointing up, right, down, left, up, which goes clockwise
instead.
igloo myrtilles fourmis
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Yes I once tried to solve the reason behind it but failed. So I guess it's probably beautiful coincidence.
X'(y-Xβ)=0
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