# exponential

• March 24th 2006, 11:36 PM
rachael
exponential
20 The number of parts per million, x, of E. coli in a stream t hours after a pollutant containing E. coli is introduced is modelled by
x(t) = loge (t + e^2), t ≥ 0.
a How many parts per million of E. coli are introduced into the stream?
how do i work out this question?
• March 25th 2006, 06:57 AM
earboth
Quote:

Originally Posted by rachael
20 The number of parts per million, x, of E. coli in a stream t hours after a pollutant containing E. coli is introduced is modelled by
x(t) = loge (t + e^2), t ≥ 0.
a How many parts per million of E. coli are introduced into the stream?
how do i work out this question?

Hello,

I'm not quite certain, but it looks to me as if you were seeking for the start value. If I'm right, then you have to calculate x(0):
$x(0) = log_e (0 + e^2)=2$

I'm not very much aquainted to E. coli but the result seems a little bit small to me.

Greetings

EB