# make p the subject.

• Sep 12th 2009, 03:57 AM
Khonics89
make p the subject.
find an explicit formula for P in terms of t....

I'm struggling with this one :(

I know we can do dt/dP = 1/p(2-0.01p)

then apply partial fractions.. and then integerate and then .... thats when its gets abit tricky.

to find C... t=0 when P=50

I forgot what that something is...

Thanks(Rofl)
• Sep 12th 2009, 04:55 AM
Matt Westwood
Sorry, you've confused me ... what's the equation you're trying to solve?
• Sep 12th 2009, 04:59 AM
e^(i*pi)
Quote:

Originally Posted by Matt Westwood
Sorry, you've confused me ... what's the equation you're trying to solve?

$\displaystyle \frac{dt}{dP} = \frac{1}{p(2-0.01p)}$

(under edit while fixing mistakes)

$\displaystyle dt = \frac{dP}{p(2-0.01p)} = \frac{A}{p} + \frac{B}{2-0.01p}$

$\displaystyle \frac{1}{p(2-0.01p)} = \frac{(2-0.01p)A + Bp}{p(2-0.01p)}$
• Sep 12th 2009, 05:14 PM
Khonics89
Yes, I've done that and went abit further..

then we find the values of a and b which are 1/2 and 1/200 respectively.

then we find C...

then the problem is when I make P the subject ??
• Sep 12th 2009, 05:15 PM
Khonics89
The equation is dt/dp= 1/p(1-0.01P)

to find the constant C use when t=0 P=50 ...