# Chain Rulled UNLEASED!

1. Oct 7, 2004

### Spectre32

OK I have this problem
Code (Text):
dw/dt = w = r^2-s*tan(v)
And it gives the following:
Code (Text):
r = sin^2(t)  s = cos(t) v = 4t
Soo.....now Do i derive those still with respect to all those values? Or can i knock them all out in a line or two.

2. Oct 7, 2004

### stunner5000pt

i don't quite understand how dw/dt = w

3. Oct 7, 2004

### Spectre32

No it's right... I think it's just saying that They want your answer to be liek
W = 'xxxxxxx'

4. Oct 7, 2004

### arildno

It is incorrect; period.
the only functions satisfying dw/dt=w is w(t)=Ke^t for some K.
This does NOT agree with the last equality.

5. Oct 7, 2004

### Spectre32

Hmmm whoops... this is how the problem reads: Find dw/dt if
w = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'

6. Oct 7, 2004

### arildno

Count the number of x's you've got, then UNLEASH the chain rule.

7. Oct 7, 2004

### Spectre32

.... There are no X's in that problem. As i said is it best to go through and derive them all at once or so i gotta like derive and multiply what each value holds. Everything Must be in terms of t

8. Oct 8, 2004

### arildno

You wrote:

"w = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'"

I know what you meant, now; you should have explicitly written that this was a substitute for the expression given in post 1.

9. Oct 8, 2004

### Spectre5

You know what each part is in terms of t...that is what everyone is saying....now just bust out the product and chain rule.....you hsould get the answer

we almost have the same name...