Question

a recreational swimming lake is treated to control bacteria. suppose t days after a treatment the concentration of bacteria per cubic centimeter is given by c(t)=30t^2-240t+500; 0 12 years ago

Answer 1

differentiate
60t - 240 = 0 for minmm
t = 6 days

minm concentrtation is
30(36) - 240*6 + 500
= 1080 - 1440 + 500
= 140

Answer 2

oh sorryyyyy - i cant count! t = 4 days!
minm concentration
= 30*16 - 240*4 + 500

Answer 3

do u follow that ok ?

Answer 4

my brain did a 'switch off' for a moment

Answer 5

yeah i think! so the minimum concentration would be 20?

Answer 6

480 -960 + 500 = 20
right

Answer 7

awesome thanks so much!!!

Answer 8

no probs