If someone could please help with this problem that would be great.
The unhealed area, A, of certain skin wound after t days is modelled by the formula
A = 100(10)^-0.2t where A is measured in cm^2
(i) What area, to the nearest cm^2, will be left unhealed after 2 days?
(ii) After how many days will the wound be 70% healed?
2007-08-19 13:51:32 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
For the first part of the question, just plug 2 in for t. For the second part, you need to know what the initial unhealed area is, for that just set t = 0 and see what number you get. Then take 30% of that number (for 70% healed), plug it back in the formula and solve for t.
2007-08-19 13:57:22 · answer #1 · answered by pegminer 7 · 0⤊ 0⤋
A = 100(10)^-0.2t
A(2) = 100(10^(-.2*2))=39.81 cm^2 = 40 cm^2
a(0)=100 cm
a(t)=30
30=100(10)^-0.2t
t=2.61 days
2007-08-19 20:53:40 · answer #2 · answered by bradlelf 2 · 0⤊ 1⤋