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#1 2007-01-24 19:20:59
- Toast
- Real Member
- Registered: 2006-10-08
- Posts: 1,321
Examples on Wiki
I tested out the last few examples on this page:
Wikipedia Examples
against my calculator, and it came up with
for #1
and for #2:
Why is this?
And isn't the last equation that they have algebraically incorrect anyway, because it doesn't keep the negative sign?
Last edited by Toast (2007-01-24 19:22:33)
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#2 2007-01-25 00:29:07
- mathsyperson
- Moderator
- Registered: 2005-06-22
- Posts: 4,900
Re: Examples on Wiki
The article is fully correct. For the first example, you copied their final result wrongly.
They had
, which is the same as yours but written differently.For the second, they had
, which is also correct. They differentiated cosx to give -sinx, then they took the negative of that, which is what they said to do in that method that they explained.I have no idea why your calculator wanted a π/180 in there. It looks like it might have been switching between degrees and radians or something.
Why did the vector cross the road?
It wanted to be normal.
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