(B) The volume is composed of elements of the form ΔV = (2x)^2 Δy. If h
is the depth, in feet, then, after t hr,
(B) Separating variables yields
Then
P(t) = 1000 − ce−kt.
P(0) = 300 gives c = 700. P(5) = 500 yields 500 = 1000 − 700e−^5 k, so k
+ 0.0673. Now P(10) = 1000 − 700e−0.673 643.
(C) arctan 1 = π. H′(1) = f (1) = 2.
The equation of the tangent line is y − π = 2(x − 1).
(C) Using midpoint diameters to determine cylinders, estimate the