Solve.The radioactive decay of radon 222 can be described by the equation A = Ce-0.1813t, where C is the original amount of radon and A is the amount of radon after t days. If 1.4 milligrams are in a laboratory container today, how much was there is the container 3 days ago? Round to the nearest hundredth.
A. 2.41 mg
B. 2.21 mg
C. 0.81 mg
D. 2.07 mg
Answer: A
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Solve the problem.dy/dt = ky + f(t) is a population model where y is the population at time t and f(t) is some function to describe the net effect on the population. Assume k = .02 and 
when t = 0. Solve the differential equation of y when f(t) = -19t.
A. y = 950t + 47,500 - 37,500e.02t B. y = -950t - 47,500 - 37,500e.02t C. y = 950t + 47,500 - 37,500e-.02t D. y = -950t + 47,500 - 37,500e-.02t
Give a geometric description of the set of points whose coordinates satisfy the given conditions. x2 + y2 + z2 > 16
A. All points in space B. All points on the surface of the cylinder with radius 4 C. All points outside the cylinder with radius 4 D. All points outside the sphere of radius 4
For the function represented in the graph, determine the domain or range, as requested.Find the range.
A. {y? -5 ? x ? 3} B. {y? -2 ? x ? 2} C. {-5, -4, -3, -2, -1, 0, 1, 2, 3} D. {-4, -3, -2, -1, 0, 1, 2, 3, 4}
Solve. Round to the nearest tenth.Shane is flying his kite on 38 yd of string. The kite is directly above the edge of a pond. The edge of a pond is 26 yd from where the kite is tied to the ground. How far is the kite above the pond?
A. 768 yd B. 27.7 yd C. 46 yd D. 2120 yd