CHAPTER 0 PRELIMINARIES
SECTION 0.5 Functions and Their Graphs
Problem Set 0.5, Number 1 – 30.
- For f(x) = 1 – x2 find each value.
- For F(x) = x3 + 3x , find each value.
- For G(y) = 1/(y – 1) find each value.
- For Φ(u) = (u + u2)/(√(u)), find each value. (Φ is the uppercase Greek letter phi.)
- For
- For
- Which of the following determine a function f with formula y = f(x)? For those that do, find f(x). Hint: Solve for y in terms of x and note that the definition of a function requires a single y for each x.
- Which of the graphs in Figure 12 are graphs of functions?
- For f(x) = 2x2 – 1, find and simplify [f(a + h) – f(a)]/h.
- For F(t) = 2t3, find and simplify [F(a + h) – f(a)]/h.
(a)
|
f(1)
|
(b)
|
f(–2)
|
(c)
|
f(0)
|
(d)
|
f(k)
|
(e)
|
f(–5)
|
(f)
|
f1/4
|
(g)
|
f(1 + h)
|
(h)
|
f(1 + h) – f(1)
|
(i)
|
f(2 + h) – f(2)
|
💬 SOLUTION:
a.
|
f(1) = 1 – 12 = 0
|
b.
|
f(–2) = 1 – (–2)2 = –3
|
c.
|
f(0) = 1 – 02 = 1
|
d.
|
f(k) = 1 – k2
|
e.
|
f(–5) = 1 – (–5)2 = –24
|
f.
|
f(1/4) = 1 – (1/4)2
= 1 – 1/16 = 15/16
|
g.
|
f(1 + h) = 1 – (1 + h)2 = –2h – h2
|
h.
|
f(1 + h) – f(1) = –2h –
h2 – 0 = –2h – h2
|
i.
|
f(2 + h) – f(2) = 1 – (2 + h)2 + 3 = –4h
– h2
|
(a)
|
F(1)
|
(b)
|
F(√(2))
|
(c)
|
F(1/4)
|
(d)
|
F(1 + h)
|
(e)
|
F(1 + h) – F(1)
|
(f)
|
F(2 + h) – F(2)
|
💬 SOLUTION:
a.
|
F(1) = 13 + 3 × 1 = 4
|
b.
|
F(√(2)) = (√(2))3 + 3(√(2)) = 2√(2) + 3√(2) = 5√(2)
|
c.
|
F(1/4) = (1/4)3
+ 3(1/4) = 1/64 + 3/4
= 49/64
|
d.
|
F(1 + h) = (1 + h)3 + 3(1 + h)
F(1 + h) = 1 + 3h + 3h2 + h3
+ 3 + 3h
F(1 + h) = 4 + 6h + 3h2 + h3
|
e.
|
F(1 + h) – 1 = 3 + 6h + 3h2 + h3
|
f.
|
F(2 + h) – F(2)
= (2 + h)3 + 3(2 + h)
– [23 – 3(2)]
= 8 + 12h + 6h2 + h3
+ 6 + 3h – 14
= 15h + 6h2 + h3
|
(a)
|
G(0)
|
(b)
|
G(0.999)
|
(c)
|
G(1.01)
|
(d)
|
G(y2)
|
(e)
|
G(–x)
|
(f)
|
G(1/x2)
|
💬 SOLUTION:
a.
|
G(0) = 1/(0 – 1) = –1
|
b.
|
G(0.999) = 1/(0.999 – 1) = –1000
|
c.
|
G(1.01) = 1/(1.01 – 1) = 100
|
d.
|
G(y2) = 1/(y2 – 1)
|
e.
|
G(–x) = 1/(–x – 1) = – [1/(x + 1)]
|
f.
|
G(1/(x2)) = 1/([1/(x2)] – 1)
= (x2)/(1 – x2)
|
(а)
|
Φ(1)
|
(b)
|
Φ(–t)
|
(c)
|
Φ(1/2)
|
(d)
|
Φ(u + 1)
|
(e)
|
Φ(x2)
|
(f)
|
Φ(x2 + x)
|
💬 SOLUTION:
a.
|
Φ(1) = (1 + 12)/(√(1))
= 2
|
b.
|
Φ(–t) = (–t + (–t)2)/(√(–t))
= (t2 – t)/(√(–t))
|
c.
|
Φ(1/2) = (1/2 +
(1/2)2)/(√(1/2)) = 3/4/(√(1/2)) ≈
1.06
|
d.
|
Φ(u + 1) = ((u + 1) + (u
+ 1)2)/(√(u + 1)) = (u2 + 3u +
2)/(√(u + 1))
|
e.
|
Φ(x2) = ((x2) + (x2)2)/(√(x2)) = (x2 + x4)/|x|
|
f.
|
Φ(x2 + x) = ((x2
+ x) + (x2 + x)2)/(√(x2 + x))
= (x4 + 2x3 + 2x2 + x)/(√(x2
+ x))
|
f(x)
|
=
|
1
|
√(x – 3)
|
find each value.
a.
|
f(0.25)
|
b.
|
f(π)
|
c.
|
f(3 + √(2))
|
💬 SOLUTION:
a.
f(0.25)
|
=
|
1
|
√(0.25 – 3)
|
||
f(0.25)
|
=
|
1
|
√(–2.75)
|
is not defined
b.
f(x)
|
=
|
1
|
√(π – 3)
|
||
f(x)
|
≈
|
2.658
|
c.
f(3 + √(2))
|
=
|
1
|
√(3 + √(2) – 3)
|
||
f(3 + √(2))
|
=
|
1
|
√(√(2))
|
||
f(3 + √(2))
|
=
|
2–0.25
|
f(3 + √(2))
|
≈
|
0.841
|
f(x)
|
=
|
√(x2
+ 9)
|
x – √(3)
|
find each value.
a.
|
f(0.79)
|
b.
|
f(12.26)
|
c.
|
f(√(3))
|
💬 SOLUTION:
a.
f(0.79)
|
=
|
√((0.79)2
+ 9)
|
0.79 – √(3)
|
||
|
≈
|
–3.293
|
b.
f(12.26)
|
=
|
√((12.26)2
+ 9)
|
12.26 – √(3)
|
||
|
≈
|
1.199
|
c.
f(√(3))
|
=
|
√((√(3))2
+ 9)
|
√(3) – √(3)
|
||
|
;
|
undefined
|
a.
|
x2 +
y2 = 1
|
b.
|
xy + y + x = 1, x ≠ –1
|
c.
|
x = √(2y + 1)
|
d.
|
x = y/(y + 1)
|
💬 SOLUTION:
a.
x2 + y2
|
=
|
1
|
y2
|
=
|
1 – x2
|
y
|
=
|
±√(1 – x2)
|
|
;
|
not a function
|
b.
xy + y + x
|
=
|
1
|
y(x + 1)
|
=
|
1 – x
|
y =
|
1 – x
|
|
x + 1
|
||
; f(x)
=
|
1 – x
|
|
x + 1
|
c.
x
|
=
|
√(2y + 1)
|
x2
|
=
|
2y + 1
|
y =
|
x2 – 1
|
|
2
|
||
; f(x)
=
|
x2 – 1
|
|
2
|
d.
x =
|
y
|
|
y + 1
|
||
xy + x
|
=
|
2y + 1
|
x
|
=
|
y – xy
|
x
|
=
|
y(1 – x)
|
y =
|
x
|
|
1 – x
|
||
; f(x)
=
|
x
|
|
1 – x
|
This problem suggests a rule: For a graph to be the graph of a function, each vertical line must meet the graph in at most one point.
💬 SOLUTION:
The graphs on the left are not graphs of functions, the graphs on the right are graphs of functions.
💬 SOLUTION:
f(a + h) – f(a)
|
=
|
[2(a + h)2
– 1] – (2a2
– 1)
|
h
|
h
|
|
|
=
|
4ah + 2h2
|
|
h
|
|
|
=
|
4a + 2h
|
💬 SOLUTION:
F(a + h) – F(a)
|
=
|
4(a + h)3
– 4a3
|
h
|
h
|
|
=
|
4a3
+ 12a2h + 12ah2
+ 4h3 – 4a3
|
h
|
||
|
=
|
12a2h
+ 12ah2 + 4h3
|
h
|
||
|
=
|
12a2 + 12ah + 4h2
|
BACA JUGA:
|
|
- For g(u) = 3/(u – 2), find and simplify [g(x + h) – f(x)]/h.
- For G(t) = t/(t + 4), find and simplify [G(a + h) – f(a)]/h.
- Find the natural domain for each of the following.
- Find the natural domain in each case.
- f(x) = – 4
- f(x) = 3x
- F(x) = 2x + 1
- F(x) = 3x – √2
- g(x) = 3x2 + 2x – 1
- g(u) = u3/8
💬 SOLUTION:
g(x + h) – g(x)
|
|
3
|
–
|
3
|
=
|
x + h – 2
|
x – 2
|
||
h
|
h
|
|
|
3x – 6 – 3x
– 3h + 6
|
=
|
x2 – 4x + hx – 2h + 4
|
|
h
|
||
|
=
|
–3h
|
h(x2 – 4x + hx
– 2h + 4)
|
|
=
|
–
|
3
|
x2 – 4x + hx – 2h + 4
|
💬 SOLUTION:
G(a + h) – G(x)
|
|
a + h
|
–
|
a
|
=
|
a + h + 4
|
a + 4
|
||
h
|
h
|
|
|
a2 + 4a + ah + 4h – a2 – ah – 4a
|
=
|
a2 + 8a + ah + 4h + 16
|
|
h
|
|
=
|
4h
|
h(a2 + 8a + ah
+ 4h + 16)
|
|
=
|
4
|
a2 + 8a + ah + 4h + 16
|
a.
|
F(z) = √(2z + 3)
|
b.
|
G(v) = 1/(4v – 1)
|
c.
|
Ψ(x) = √(x2 – 9)
|
d.
|
H(y) = – √(625 – y4)
|
💬 SOLUTION:
a. F(z) = √(2z + 3)
2z + 3 ≥ 0; z ≥ –(3/2)
Domain: {z ∈ ℝ : z ≥ –(3/2)}
b. g(v) = 1/(4v – 1)
4v – 1 = 0; v = ¼
Domain: {v ∈ ℝ : v ≠ ¼}
c. Ψ(x) = √(x2 – 9)
x2 – 9 ≥ 0; x2 ≥ 9; |x| ≥ 3
Domain: {x ∈ ℝ : |x| ≥ 3}
d. H(y) = –√(625 – y4)
625 – y4 ≥ 0; 625 ≥ y4; |y| ≤ 5
Domain: {y ∈ ℝ : |y| ≤ 5}
a.
|
f(x) = (4 – x2)/(x2 – x
– 6)
|
b.
|
G(y) = √(y + 1)–1
|
c.
|
Φ(u) = |2u + 3|
|
d.
|
F(t) = t2/3 – 4
|
💬 SOLUTION:
a. f(x) = (4 – x2)/(x2 – x – 6) = (4 – x2)/[(x – 3)(x + 2)]
Domain: {x ∈ ℝ : x ≠ –2, 3}
b. G(y) = √[(y + 1)–1]
1/(y + 1) ≥ 0; y > –1
Domain: {y ∈ ℝ : y > –1}
c. Φ(u) = |2u + 3|
Domain: ℝ (all real numbers)
d. F(t) = t2/3 – 4
Domain: ℝ (all real numbers)
In Problems 15–30, specify whether the given function is even, odd, or neither, and then sketch its graph.
💬 SOLUTION:
f(x) = –4; f(–x) = –4; even function
💬 SOLUTION:
f(x) = 3x; f(–x) = –3x; odd function
💬 SOLUTION:
F(x) = 2x + 1; F(–x) = –2x + 1; neither
💬 SOLUTION:
F(x) = 3x – √2; F(–x) = –3x – √2; neither
💬 SOLUTION:
g(x) = 3x2 + 2x – 1; g(–x) = 3x2 – 2x – 1; neither
💬 SOLUTION:
g(u) = u3/8; g(–u) = –(u3/8); odd function
BACA JUGA:
|
|
- g(x) = x/(x2 – 1)
- Φ(z) = (2z + 1)/(z – 1)
- f(w) = √(w – 1)
- h(x) = √(x2 + 4)
- f(x) = |2x|
- F(t) = –|t + 3|
- g(x) = 〚x/2〛
- G(x) = 〚2x – 1〛
💬 SOLUTION:
g(x) = x/(x2 – 1); g(–x) = (–x)/(x2 – 1); odd
💬 SOLUTION:
Φ(z) = (2z + 1)/(z – 1); Φ(–z) = (–2z + 1)/(–z – 1); neither
💬 SOLUTION:
f(w) = √(w – 1); f(–w) = √(–w – 1); neither
💬 SOLUTION:
h(x) = √(x2 + 4); h(–x) = √(x2 + 4); even function
💬 SOLUTION:
f(x) = |2x|; f(–x) = |–2x| = |2x|; even function
💬 SOLUTION:
F(t) = –|t + 3|; F(–t) = –|–t + 3|; neither
💬 SOLUTION:
g(x) = 〚x/2〛; g(–x) = 〚–x/2〛; neither
💬 SOLUTION:
G(x) = 〚2x – 1〛; G(–x) = –〚2x – 1〛; neither
g(t)
|
=
|
{
|
1
|
if t ≤ 0
|
t + 1
|
if 0 < t < 2
|
|||
t2 –
1
|
if t ≥ 2
|
💬 SOLUTION:
g(t)
|
=
|
{
|
1
|
if t ≤ 0
|
t + 1
|
if 0 < t < 2
|
|||
t2 –
1
|
if t ≥ 2
|
; neither
h(x)
|
=
|
{
|
–x2 + 4
|
if x ≤ 1
|
3x
|
if x > 1
|
💬 SOLUTION:
h(x)
|
=
|
{
|
–x2 + 4
|
if x ≤ 1
|
3x
|
if x > 1
|
; neither
BACA JUGA:
|
|
Demikian soal serta penjelasan untuk Pembahasan Soal Buku Calculus 9th Purcell Chapter 0 - 0.5 Number 1 – 30. Silahkan untuk berkunjung kembali dikarenakan akan selalu ada update terbaru 😊😄🙏. Silahkan juga untuk memilih dan mendiskusikan di tempat postingan ini di kolom komentar ya supaya semakin bagus diskusi pada setiap postingan. Diperbolehkan request di kolom komentar pada postingan ini tentang rangkuman atau catatan atau soal dan yang lain atau bagian hal yang lainnya, yang sekiranya belum ada di website ini. Terima kasih banyak sebelumnya 👍. Semoga bermanfaat dan berkah untuk kita semua. Amiiinnn 👐👐👐
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