Step-by-step explanation:
P(t) = 12,000 (2)^(-t/15)
9,000 = 12,000 (2)^(-t/15)
0.75 = 2^(-t/15)
ln(0.75) = ln(2^(-t/15))
ln(0.75) = (-t/15) ln(2)
-15 ln(0.75) / ln(2) = t
t = 6.23
I believe it should be .3 because its rounded to the nearest tenth
Answer:
k = 30, 
Step-by-step explanation:
Since 
is a solution, then it must satisfy the differential equation. So, we calculate the derivatives and replace the value in the equation. We have that
Then, replacing the derivatives in the equation we have:
Since 
is a positive function, we have that
.
Now, consider a general solution 
, then, by calculating the derivatives and replacing them in the equation, we get
We already know that r=5 is a solution of the equation, then we can divide the polynomial by the factor (r-5) to the get the other solution. If we do so, we get that (r-6)=0. So the other solution is r=6.
Therefore, the general solution is
You have to searh the x values that make f(x) = 0
Factoring this equation is very difficult.
You can divide by x+3 and you will find that the equation can be factored as
(x+3)(x-4)^2
That means that x = -3 and x = 4 make f(x) = 0
Then the points are (-3,0) and (4,0).
