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Math 151 WIR, Spring 2014, Benjamin
Aurispa
Math 151 Week in Review 11
Sections 5.1, 5.2, & 5.3
1. Given the graph of f ′ below, find the following. Then sketch a possible graph of f if f is continuous
and f (−6) = 0.
(i) The intervals where f is increasing and decreasing.
(ii) The x-values of any local extrema of f .
(iii) The intervals where f is concave up and concave down.
(iv) The x-values of any inflection points of f .
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
2. Sketch a graph of a function f with the following properties:
(i) f is continuous everywhere except at x = 3.
(ii) lim f (x) = 0
x→±∞
(iii) lim f (x) = ∞, lim f (x) = −∞
x→3−
x→3+
(iv) f (0) = −3, f (7) = 3
(v) f ′ (x) > 0 on (−2, 3) ∪ (3, 7)
(vi) f ′ (x) < 0 on (−∞, −2) ∪ (7, ∞)
(vii) f ′′ (x) > 0 on (−5, 3) ∪ (5, 7) ∪ (7, ∞)
(viii) f ′′ (x) < 0 on (−∞, −5) ∪ (3, 5)
3. Find all absolute and local extrema for the following functions by graphing.
(a) f (x) = x2 − 3, −1 ≤ x ≤ 2
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
(b) f (x) =
(
x+2
−(x − 2)2 + 3
if − 2 < x ≤ 0
if 0 < x < 3
4. Find all critical values for the following functions.
1
(a) f (x) = x 3 (x − 1)2
(b) f (x) =
x+5
ex
(c) f (x) = |x2 − 5x|
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
5. Find the absolute maximum and minimum values for the following functions on the given interval.
(a) f (x) = x4 − 8x2 + 1 on [−1, 3]
(b) f (x) = x + 2 sin x on [0, π]
(c) f (x) =
√
3
x2 − 6x on [−1, 4]
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
(d) f (x) =
1
on [1, 3]
(x − 2)2
6. Sketch a possible graph with the following properties.
(a) x = 3 is a critical number of f , but f has no local extrema.
(b) f is continuous and has a local minimum at x = 3, but f ′ (3) does not exist.
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
7. Find the value of c that satisfies the Mean Value Theorem for the function f (x) = 3 − x2 on the
interval [1, 6].
8. For an object with position function s(t) where s is in ft and t is in seconds, it is known that s(0) = −12
and s(3) = 15. Show that at some point between t = 0 and t = 3, the object’s instantaneous velocity
is 9 ft/s.
9. Determine all intervals where the function f (x) = x6 − 6x5 is increasing and decreasing, concave up
and concave down. Identify all local extrema and points of inflection.
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
10. Find the intervals where the following functions are increasing/decreasing and identify all local extrema.
(a) f (x) = xe−2x
(b) f (x) =
2
x+3
(x − 2)2
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
(c) f (x) = (x − π2 ) cos x − sin x on [0, 2π]
11. Find the intervals where the following functions are concave up and concave down and identify all
inflection points.
(a) f (x) = ex (x3 − 8x2 + 27x − 38)
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Math 151 WIR, Spring 2014, Benjamin
Aurispa
(b) f (x) = (3 − ln x)3
12. Find a function of the form f (x) = ax3 + bx2 + cx + d that has a local maximum of 12 at x = 0 and a
local minimum of 4 at x = 2.
13. Given the following information, identify any local extrema.
x
−3
4
6
8
f (x)
1
5
3
4
f ′ (x)
0
0
0
DNE
f ′′ (x)
−4
0
12
DNE
9