# Thread: make p the subject.

1. ## 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

2. Sorry, you've confused me ... what's the equation you're trying to solve?

3. 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)

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

$\displaystyle \frac{1}{p(2-0.01p)} = \frac{(2-0.01p)A + Bp}{p(2-0.01p)}$

4. 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 ??

5. The equation is dt/dp= 1/p(1-0.01P)

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