Fall 2009 Math 151
Night Before Drill for Exam II
4
Setion 3.6
1. Find the slope of the line tangent to the
urve given by −xy 2 + 3y 3 = −3 at the point
(0, −1).
ourtesy: David J. Manuel
(overing 3.3 - 4.2)
2. Find
1
3. Show that the urves x2 + y 2 = 2y and x2 +
y 2 = 4x are orthogonal.
Setion 3.3
1. A partile is moving along a straight line with
position equation s = f (t) = t2 −2t+3, where
t is in seonds and s is in feet.
5
dy
given y 2 + xy = 8.
dx
Setion 3.7
1. The position of a partile is given by r(t) =
(e−2t cos(2t))i + (e−2t sin(2t))j. Find the veloity and speed of the partile when t = 0.
(a) When is the partile at rest?
(b) Find the distane traveled by the partile during the rst 4 seonds.
2. Given the urve r(t) = (6 sin t)i + (3 cos t)j ,
nd a unit tangent vetor at the point where
π
t= .
2. A tank ontains 2000 liters of pure water. A
brine solution ontaining 20 grams of salt per
liter of water is pumped into the tank at a
rate of 40 liters per minute. Find the rate
of hange in the onentration of the solution
after 10 minutes.
3
6
Setion 3.8
1. Let f (x) = (1 + x2 )3/2 . Find f ′′ (0).
2
2. Find the 20th derivative f 20 (x) of f (x) = xex .
Setion 3.4
3. The graphs of f, f ′ ,and f ′′ are shown below.
Determine whih graph eah one is.
3 cos x − 3 + 4 sin x
1. Compute lim
x→0
5x
sin2 (8x)
.
x→0
9x2
2. Compute lim
3. Find all values of x between 0 and 2π where
the tangent line to f (x) = 2x − tan x is horizontal.
3
Setion 3.5
1. Given f (x) = sin4 x, ompute f ′
π .
3
√
2. Find the derivative of f (x) = cos x2 + 1.
7
Setion 3.9
1. Given the urve parametrized by x = t2 , y =
t3 − 3t, nd the equation of the tangent line
at the point (4, −2).
3. Suppose f is a dierentiable funtion suh
that f (1) = 6, f ′ (1) = −2, f (3) = 6, f ′ (3) =
4, f (6) = 5, f ′ (6) = −1, f (9), and f ′ (9) = 1.
2. Find the points on the urve x = t3 −3t2 −9t+
1, y = t3 + 3t2 − 9t + 1 at whih the tangent
line is horizontal or vertial (indiate whih).
(a) If g(x) = (f (x))3 ,nd g ′ (3)
(b) If h(x) = f (f (x)), nd h′ (3)
1
8
11
Setion 3.10
4x + 3
1. A man 6 feet tall is walking at the rate of
3 ft/se away from a ground-level spotlight
toward a wall whih is 18 feet away. How fast
is his shadow on the wall hanging when he is
10 feet from the spotlight?
1. The funtion f (x) =
is one-to-one.
2x + 1
−1
′
Let g = f . Find g (1).
2. Given f is a one-to-one funtion with f (4) =
2, f ′ (4) = −3, f (2) = 6, f ′ (2) = −5, f (6) =
4, and f ′ (6) = −1. If g = f −1 , nd g ′ (2).
2. Fifty meters from a launhing pad, a man observes a heliopter taking o. The heliopter
lifts o vertially and rises at a speed of 52
m/se. At the instant its height is 120m, how
fast is the distane between the heliopter and
the man hanging?
3. The funtion f (x) = x3 − 2x2 + 5x is one-toone. Let g = f −1 . Find g ′ (10).
3. Sand is being dumped into a tank in the shape
of a one whose radius is 6 meters and height
is 8 meters. If the sand is pouring in at a rate
of 100 m3 per seond, how fast is the height
of the sandpile inreasing when the height is
1
75 m? The volume of a one is V = πr2 h.
3
9
Setion 3.11
1. Use dierentials
or linear approximation to
√
estimate 3 8.012.
2. √
Find the linear approximation to f (x) =
1 + 2x near x = 0.
3. Find the quadrati approximation to f (x) =
π
cos x near x = .
6
10
Setion 4.1
1. Compute lim−
x→0
2
.
1 + ecot x
2. Find the rst and seond derivatives of f (x) =
ex
3
Setion 4.2
+x
3. Show that the funtion y = Cxe−2x (C is a
onstant) is a solution to the dierential equation y ′′ + 4y ′ + 4y = 0.
2