Kunci Jawaban Matematika Sukino
Matematika Peminatan Sukino Kelas XII
Limit Fungsi Aljabar dan Fungsi Trigonometri
LKS 2
Soal dan Pembahasan Matematika Sukino Peminatan
Bagian B
2. Hitung nilai setiap limit trigonometri berikut.
a.
lim x→0
sin (1 - cos x)
---------------- =
x
2
b.
lim x→0
tan (cos 4x - 1)
------------------ =
3x . sin (4/3)x
c.
lim x→0
sin[2 - 2 cos (x + 2)]
------------------------- =
x
2 + 4x + 4
Jawaban :
a.
lim x→0
sin (1 - cos x)
---------------- =
x2
lim x→0
sin (1 - cos x) (1 - cos x)
---------------- . -------------- =
x
2 (1- cos x)
lim x→0
sin (1 - cos x) (1 - cos x)
---------------- . -------------- =
(1- cos x) x
2
lim x→0
(1 - cos x)
1 . -------------- =
x
2
lim x→0
2 sin 1/2 x sin 1/2 x
------------------------- =
x
2
2 . 1/2 . 1/2 = 1/2
----------------------------------------------------------------------------------------------------------
b.
lim x→0
tan (cos 4x - 1)
------------------ =
3x . sin (4/3)x
lim x→0
tan (cos 4x - 1) (cos 4x - 1)
------------------ . ---------------- =
3x . sin (4/3)x (cos 4x - 1)
lim x→0
tan (cos 4x - 1) (cos 4x - 1)
------------------ . ---------------- =
(cos 4x - 1) 3x . sin (4/3)x
lim x→0
(cos 4x - 1)
--------------- =
3x sin (4/3)x
lim x→0
- (1 - cos 4x)
--------------- =
3x sin (4/3)x
lim x→0
-1 2 sin 2x sin 2x
-- . ------------------ =
3 x sin (4/3)x
-1/3 . 2 . 2 . 2 . 3/4
= -2
----------------------------------------------------------------------------------------------------------
c.
lim x→0
sin[2 - 2 cos (x + 2)]
------------------------- =
x
2 + 4x + 4
lim x→0
sin[2 - 2 cos (x + 2)] [2 - 2 cos (x + 2)]
------------------------- . ---------------------- =
x
2 + 4x + 4 [2 - 2 cos (x + 2)]
lim x→0
sin[2 - 2 cos (x + 2)] [2 - 2 cos (x + 2)]
------------------------- . ---------------------- =
[2 - 2 cos (x + 2)] x
2 + 4x + 4
lim x→0
[2 - 2 cos (x + 2)]
---------------------- =
x
2 + 4x + 4
lim x→0
2 ( 1 - cos (x + 2))
---------------------- =
x
2 + 4x + 4
menggunakan turunan
sin (x+2)
2 . lim x→0 -------------=
2x + 4
sin (x+2)
2 . lim x→0 -------------=
2 (x + 2)
2 . 1/2 = 1
>> soal bag B no 3