Практикум по дифференциальному исчислению. Магазинников Л.И - 203 стр.

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202 Ответы
13.4. а)
18x
(4 9x
2
)
2
; б)
9x
p
(16 9x
2
)
3
; в)
18x
(4 + 9x
2
)
2
;
г) e
x
2
+2x+2
£
(2x + 2)
2
+ 2
¤
;
д) 2
sin
3
x
ln 2
¡
9 sin
4
x · cos
2
x · ln 2 + 6 sin x · cos
2
x 3 sin
3
x
¢
.
13.5. а) y
0
= ln x + 1, y
00
=
1
x
, y
(n)
=
(1)
n
(n 2)!
x
n1
;
б) y
0
= 1
1
(x 1)
2
, y
(n)
=
(1)
n
n!
(x 1)
n+1
, n = 2, 3, 4, . . .;
в)
1
2
n
6
n
sin
³
6x + n
π
2
´
2
n
sin
³
2x + n
π
2
´o
;
г)
2(1)
n
· n!
(x + 4)
n+1
+
3(1)
n
· n!
(x + 5)
n+1
; д) (1)
n+1
(n 1)!
·
1
(x + 1)
n
+
1
(x 1)
n
¸
;
е)
2(1)
n
n!
(1 + x)
n+1
; ж) 4
n
e
4x+3
.
13.6. а) x
2
sin x + 20x cos x + 90 sin x; б) x ch x + 100 sh x;
в) 3
x
x
2
(ln 3)
20
+ 40 · 3
x
· x(ln 3)
19
+ 380(ln 3)
18
3
x
;
г) (1)
n1
2
n
(2n 5)!!(x 1)
(12n)/2
;
д) (1)
n
e
x
£
x
2
2nx + n(n 1)
¤
.
13.7. а) y
000
=
¯
¯
¯
¯
¯
¯
1
x
x
2
¯
¯
¯
¯
¯
¯
; б) y
000
=
¯
¯
¯
¯
¯
¯
8 cos 2x
8 sin 2x
6
¯
¯
¯
¯
¯
¯
; в) y
000
= 6i cos tk;
г) y
000
= 8e
2t+3
i
1
t
2
j + 4 sin 2tk.
14.14. а) u
0
x
(M
0
) =
4
3
, u
0
y
(M
0
) =
2
3
, u
0
z
(M
0
) =
13
3
;
б) u
0
x
(M
0
) = 1, u
0
y
(M
0
) = 8, u
0
z
(M
0
) = 16;
в) u
0
x
(M
0
) = 0,6, u
0
y
(M
0
) = 0,8, u
0
z
(M
0
) = 15;
г) u
0
x
(M
0
) = 1,25, u
0
y
(M
0
) = 1,5, u
0
z
(M
0
) = 0,25.
14.16. а) u
00
xx
(M
0
) = 2, u
00
y y
(M
0
) = 4, u
00
zz
(M
0
) = 9, u
00
yx
(M
0
) = 0,
u
00
y z
(M
0
) = 6, u
00
zx
(M
0
) = 0;
б) u
00
xx
(M
0
) =
2
125
, u
00
y y
(M
0
) =
23
125
, u
00
zz
(M
0
) = 0, u
00
xy
(M
0
) =
36
125
,
u
00
zx
(M
0
) =
3
125
, u
00
y z
(M
0
) =
4
125
;
в) u
00
xx
(M
0
) = 14, u
00
yy
(M
0
) = 24, u
00
zz
(M
0
) = 0,
u
00
xy
(M
0
) = u
00
yx
(M
0
) = 0, u
00
xz
(M
0
) = u
00
zx
(M
0
) = 0,
u
00
y z
(M
0
) = u
00
zy
(M
0
) = 4;