The equation of a circle in standard form is

where (h, k) is the center of the circle, and r is the radius if the circle.
We need to find the radius and center of the circle.
We are given a diameter, so to find the center, we need the midpoint of the diameter.
M = ((-6 + 6)/2, (6 + (-2))/2) = (0, 2)
The center is (0, 2).
To find the radius, we find the length of the given diameter and divided by 2.





It’s ether 138.6 or 101.4. 123 rounded to the nearest tenth is 120 so you ether add or subtract
Answer:
A(t) = 300 -260e^(-t/50)
Step-by-step explanation:
The rate of change of A(t) is ...
A'(t) = 6 -6/300·A(t)
Rewriting, we have ...
A'(t) +(1/50)A(t) = 6
This has solution ...
A(t) = p + qe^-(t/50)
We need to find the values of p and q. Using the differential equation, we ahve ...
A'(t) = -q/50e^-(t/50) = 6 - (p +qe^-(t/50))/50
0 = 6 -p/50
p = 300
From the initial condition, ...
A(0) = 300 +q = 40
q = -260
So, the complete solution is ...
A(t) = 300 -260e^(-t/50)
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The salt in the tank increases in exponentially decaying fashion from 40 grams to 300 grams with a time constant of 50 minutes.