OT: Differentiation
Turbo Mini Forums

OK, I'm doing a project to determine the best place to sit on a bus in order to see the least vibrations from a sinusoidal road profile.

However, I have completely forgot how to differentiate and my first year maths book is at home.

Can anyone tell me the derivatives of k.Y.sinw.t and k.Y.sin(w.t+phi) with respect to time.

Thanks

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

No idea, but the internet says this

http://en.wikipedia.org/wiki/Derivative

I had a go using wikipedia, and i couldnt remember it properly.

Something about multiplying the bit in the brackets by the bit out the front then subtracting the power. But ive got no clue really.

sin goes to cos though.
So it should be something like
w.t.k.y.cos(wt)

In boost we trust

Thanks lads. I refuse to acknowledge the existance of wikipedia for college stuff though
sin goes to cos and the bit after sin must be differentiated w.r.t time so it becomes w and goes infront of the brackets. Then I don't know if the (wt+phi) needs to be broken into two seperate sin waves using one of the log table formulae

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

I could have answered this 25 years ago, but I've forgotten and my old text books are too complicated :$

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I think from memory (about 2 years) that that it splits into one long equation for a wave using one of the trig formulae.
But i never did get the hang of qualitative maths.

And ive referenced wikipedia in college before and didnt get picked up for it.

In boost we trust

OK, I have checkened out and numerically differentiated in excel

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse