= Buktikanlah identitas trigonometri berikut. 1. (1 + sin x)(1 - sin x) = cos²x 2. (sin x - cos x)2 = 1 - 2 sin x cos X 3. 3 cos²x = 3-3 sin? 4. (sin x + cos x)(sin x + cos x) = 2 sina x-15. (sin x - cos x)2 + 2 cos x sin x = 1
1. = Buktikanlah identitas trigonometri berikut. 1. (1 + sin x)(1 - sin x) = cos²x 2. (sin x - cos x)2 = 1 - 2 sin x cos X 3. 3 cos²x = 3-3 sin? 4. (sin x + cos x)(sin x + cos x) = 2 sina x-15. (sin x - cos x)2 + 2 cos x sin x = 1
Jawaban:
[tex]1). \: \: (1 + sin \: x)(1 - sin \: x) = {cos}^{2} x \\buktikan \: ruas \: kiri \\ 1 - sin \: x + sin \: x - {sin}^{2} x \\ 1 - {sin}^{2} x \\ {cos}^{2} x[/tex]
[tex]2). \: \: {(sin \: x - cos \: x)}^{2} = 1 - 2sin \: x \: cos \: x \\ buktikan \: ruas \: kiri \\ {sin}^{2} x - 2sin \: x \: cos \: x + {cos}^{2} x \\ {sin}^{2} x \: + {cos}^{2} x - 2sin \: x \: cos \: x \\ 1 - 2sin \: x \: cos \: x[/tex]
[tex]3). \: \: 3 {cos}^{2} x = 3 - 3 {sin}^{2}x \\ buktikan \: ruas \: kiri \\ 3(1 - {sin}^{2} x) \\ 3 - 3 {sin}^{2} x[/tex]
[tex]4). \: (sin \: x + cos \: x)(sin \: x + cos \: x) = 2sin \: x \: - 1 \\ butikan \: ruas \: kiri \\ {sin}^{2} x \: + sin \: x \: cos \: x + sin \: x \: cos \: x + {cos}^{2} x \\ {sin}^{2} x + {cos}^{2} x + 2sin \: x \: cos \: x \\ 1 + 2sin \: x \: cos \: x \\ 1 + sin \: 2x[/tex]
2. Sin^2 1+sin^2 2 + sin^2 3 + ..... +sin^2 89 / cos^2 1 + cos^2 2 +cos^2 3+.....+cos^2 89 =
trigonometri
[sin²1 + sin² 2 +...+sin² 88 + sin² 89] / [ cos² 1 + cos² 2 + ...+cos² 88+ cos² 89]=
.
misalkan
p= [(sin² 1 + sin² 89) +(sin² 2 + sin²88) +...+ (sin² 44+sin² 46)+sin²45
p = [(1) +(1) + ..+(1)+ (1/2 √2)²
p= 44(1) + 1/2 = 44,5
q = [(cos² 1 + cos² 89)+(cos² 2 + cos² 88) +...(cos²44+cos²46) + cos²45
q = 44(1) + 1/2 = 44.5
p/q = 1
3. Dengan menggunakan segitiga di bawah ini, carilah nilai dari sin(Ļ/6), cos(Ļ/6), sin(Ļ/3), cos(Ļ/3)! Pilih jawaban kamu. 1 sin (Ļ/6) = 1/2 = cos (Ļ/6) , cos (Ļ/3) = √3/2 = sin (Ļ/3) 2 sin (Ļ/6) = 1/2 , cos (Ļ/3) = 1/ √3 , sin (Ļ/3) = √3 , cos (Ļ/6) = √2 3 sin (Ļ/6) = 1/√2 , cos (Ļ/3) = √2 , sin (Ļ/3) = √3 , cos (Ļ/6) = 1/2 4 sin (Ļ/6)=1/2=cos (Ļ/3) , sin (Ļ/3) =√3/2= cos (Ļ/6) 5 sin (Ļ/6) = 1/2 = sin (Ļ/3) , cos (Ļ/3) = √3/2 = cos (Ļ/6)
1. sin pi/6 = 1/2 adalah sin 30 ,cos pi/6= √3/2 adlah cos 30, = sin 60
kayak gni kah di maksud??
4. 1. sin 2 alfa cos alfa - cos 2 alfa sin alfa 2. sin 3 alfa cos alfa + cos 3 alfa sin alfa
1.sin(2a-a) =sin a
2.sin(3a+a)=sin 4a
5. 1.diketahui tan =12/5 tntukan nilai cos ! 2diketahui tan =3/4 tntukan sin! buktikan 3.(sin - cos)² =1 - 2 sin 4.(1 + sin) (1- sin) = cos ² 5.1 (per) cos x sin - cos (per) sin = tan 6.1 - cos (per) sin = sin (per) 1
1. 12² + 5² = r
r = 13
cos = 5/13
2. 3² + 4² = r
r = 5
sin = 3/5
maaf cuma 2 nomor yg saya ngerti .-.
6. Sin²x+cos²x=1 dan sin x-cos x=1-√3/2. Nilai 2 sin x.cosx
[tex]\sin x - \cos x = 1 - \frac{\sqrt3}2[/tex]
[tex]kedua\ sisi\ dikuadratkan[/tex]
[tex](\sin x - \cos x)^2=(1 - \frac{\sqrt3}2)^2[/tex]
[tex]\sin^2 x + \cos^2 x - 2 \sin x \ \cos x=1^2 + \frac{\sqrt3^2}{2^2} - 2\frac{\sqrt3}2[/tex]
[tex]1- 2 \sin x \ \cos x=1 + \frac34 - \sqrt3[/tex]
[tex]1-1-\frac34+\sqrt3= 2 \sin x \ \cos x[/tex]
[tex]-\frac34+\sqrt3= 2 \sin x \ \cos x[/tex]
[tex]2 \sin x\ \cos x = \sqrt3 -\frac34[/tex]
[tex]jadi\ nilai\ 2\sin x\ \cos x \ adalah \sqrt3 -\frac34[/tex]
semoga membantu, mohon dikoreksi bila ada kesalahan
7. Sin 2, cos 2, sin(1/2) dan cos (1/2) Cos =2/5 dan 3/2 <0<2
Jawaban:
379) /890+70&64365/9-78
Jawaban:
379)/890+70&64365/9-78
Penjelasan dengan langkah-langkah:
semoga membantu
8. Diketahui: cos= 1 per 2 √3 Sin= 1 per 2 Carilah: cos pangkat 2 + sin
cos² + sin=(1/2 √3)² + 1/2 =1/4×3+1/2=3/4+1/2=3/4+2/4=5/4cos=1/2√3=x/r x=1 dan r=2√3
menggunakan phytagoras y²=√1²-(2√3)²
=√1-4√9
=√1-4×3
=√1-12
y=√11
cos²=(x/r)²=(1/√11)²=1/√11 dan sin=y/r=√11/2√3
maka cos²=sin=1/√11+√11/2√3=√11/2√10
9. Cos (x+30derajat)=.... A.1/2akar3(cos x + sin x) B.1/2akar3(cos x - sin x) C.1/2(akar 3 cos x - sin x) D.1/2 (cos x - akar 3 sin x) E.1/2(cos x + akar 3 sin x)
mohon diperiksa kembali ya.
10. ada yang bisa? tolong dibantu ya bagi yang bisa... terima kasih...buktikan bentuk berikut :a. sin a/cos a - cos a/sin a = 2 sin^2 a-1/sin a . cos ab.1/3 sin^2 a + 1/3 cos^2 a = 1/3c.tan^2 a cos^2 a + cot^2 a sin^2 a = 1d. 1 - sin a/cos a = cos a/1 + sin a
silahkan dilihat-lihat
11. jika sin 2 α = 2 sin α × cos α dan cos 2α = 1-2 sin ^2 α hitunglah a) cos (2 sin ^-1 (5/3)) b) sin (2 sin ^-1 (2/3))
Wat duyumin
0 kale (gw ngitung oy)
12. Jika sin a + cos a= 1/3 hitunglah 1) Sin a . cos a2) Sin²a + cos^3a3) Sin a - Cos a4) 1/sin a + 1/cos aharap jawab
jawab
sin A + cos A = 1/3
1)
(sin A + cos A)² = (1/3)²
sin² A+ cos² A + 2 sin A cos A = 1/9
1 + 2 sin A cos A = 1/9
2 sin A cos A = 1/9 - 1 = - 8/9
sin A cos A = - 8/18 = -4/9
3)
sin A - cos A = p
(sin A - cos A)^2 = p^2
sin² A + cos² A - 2 sin A cos A = p²
1 - (-8/9) = p²
p² = 1 +8/9 = 17/9
p = 1/3 √17
4) 1/sin A + 1/cos x =
= (sin A + cos A) /(sin x cos x)
=(1/3) / (-4/9)
= 3/4
13. bentuk sin^3 1/2m-cos ^3 1/2 m/cos 1/2m-sin 1/2 m identik dengan
(sin³ (m/2) - cos³ (m/2)) / (cos (m/2) - sin (m/2)), misal y= m/2
= (sin y - cos y).(sin² y + cos² y + sin y.cos y) / (cos y - sin y)
= -(sin² y + cos² y + sin y.cos y)
= -(1 + sin y.cos y)
= -(1 + (1/2).sin 2y)
= -(1 + (1/2).sin m)
14. Tunjukkan bahwa: 1. 2 sin (teta + 1/2 phi) cos (teta - 1/2 phi) = 2 sin teta cos teta 2. 2 sin 1/2 (alfa + beta) cos 1/2 (alfa - beta) = sin alfa + cos beta 3. 2 cos (1/4 phi + alfa) sin (1/4 phi -alfa) = 1-2 sin alfa cos alfa
1. Pembuktian 2 sin (Īø + 1/2 Ļ) cos (Īø - 1/2 Ļ) = 2 sin Īø cos Īø
2. Pembuktian 2 sin 1/2 (α + β) cos 1/2 (α - β) = sin α + cos β
3. Pembuktian 2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 1 - 2 sin α cos α
SImak pembahasan berikut mengenai penjumlahan sinus dan kosinus.
PembahasanRumus identitas penjumlahan sinus dan kosinussin (a + b) = sin a cos b + cos a sin b
sin (a - b) = sin a cos b - cos a sin b
cos (a + b) = cos a cos b - sin a sin b
cos (a - b) = cos a cos b + sin a sin b
1. Pembuktian 2 sin (Īø + 1/2 Ļ) cos (Īø - 1/2 Ļ) = 2 sin Īø cos Īø
jawab:
2 sin (Īø + 1/2 Ļ) cos (Īø - 1/2 Ļ) = 2 (sin Īø cos 1/2 Ļ + cos Īø sin 1/2 Ļ) (cos Īø cos 1/2 Ļ + sin Īø sin 1/2 Ļ)
ingat! sin 1/2 Ļ = 1 dan cos 1/2 Ļ = 0
2 sin (Īø + 1/2 Ļ) cos (Īø - 1/2 Ļ) = 2 (sin Īø × 0 + cos Īø × 1) (cos Īø × 0 + sin Īø × 1)
2 sin (Īø + 1/2 Ļ) cos (Īø - 1/2 Ļ) = 2 (0 + cos Īø) (0 + sin Īø)
2 sin (Īø + 1/2 Ļ) cos (Īø - 1/2 Ļ) = 2 cos Īø sin Īø (terbukti)
2. Pembuktian 2 sin 1/2 (α + β) cos 1/2 (α - β) = sin α + cos β
jawab:
2 sin 1/2 (α + β) cos 1/2 (α - β) = 2(sin 1/2 α cos 1/2 β + cos 1/2 α sin 1/2 β)(cos 1/2 α cos 1/2 β + sin 1/2 α sin 1/2 β)
2 sin 1/2 (α + β) cos 1/2 (α - β) = 2(sin 1/2 α cos 1/2 α cos² 1/2 β + sin² 1/2 α sin 1/2 β cos 1/2 β + cos² 1/2 α sin 1/2 β cos 1/2 β + sin 1/2 α cos 1/2 α sin² 1/2 β)
2 sin 1/2 (α + β) cos 1/2 (α - β) = 2(sin 1/2 α cos 1/2 α (cos² 1/2 β + sin² 1/2 β) + (sin² 1/2 α + cos² 1/2 α)sin 1/2 β cos 1/2 β)
ingat! sin² x + cos² x = 1
2 sin 1/2 (α + β) cos 1/2 (α - β) = 2(sin 1/2 α cos 1/2 α × (1) + (1) × sin 1/2 β cos 1/2 β)
2 sin 1/2 (α + β) cos 1/2 (α - β) = 2(sin 1/2 α cos 1/2 α + sin 1/2 β cos 1/2 β)
2 sin 1/2 (α + β) cos 1/2 (α - β) = 2 sin 1/2 α cos 1/2 α + 2 sin 1/2 β cos 1/2 β
ingat! sin 2x = 2 sin x cos x
2 sin 1/2 (α + β) cos 1/2 (α - β) = sin 2(1/2 α) + sin 2(1/2 β)
2 sin 1/2 (α + β) cos 1/2 (α - β) = sin α + sin β (terbukti)
3. Pembuktian 2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 1 - 2 sin α cos α
jawab:
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 2(cos 1/4 Ļ cos α - sin 1/4 Ļ sin α) (sin 1/4 Ļ cos α - cos 1/4 Ļ sin α)
ingat! sin 1/4 Ļ = 1/2 √2 dan cos 1/4 Ļ = 1/2 √2
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 2(1/2 √2 cos α - 1/2 √2 sin α) (1/2 √2 cos α - 1/2 √2 sin α)
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 2(1/2 √2 (cos α - sin α)) (1/2 √2 (cos α - sin α))
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 2 × 1/2 √2 × 1/2 √2 (cos α - sin α)(cos α - sin α)
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 1/2 √2 × √2 (cos α - sin α)(cos α - sin α)
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 1/2 × 2 (cos α - sin α)(cos α - sin α)
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 1(cos α - sin α)(cos α - sin α)
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = (cos α - sin α)(cos α - sin α)
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = cos² α - sin α cos α - sin α cos α + sin² α
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = cos² α + sin² α - 2 sin α cos α
2 cos (1/4 Ļ + α) sin (1/4 Ļ - α) = 1 - 2 sin α cos α (terbukti)
Pelajari lebih lanjutMenentukan himpunan penyelesaian persamaan sinus https://brainly.co.id/tugas/24817396#---------------------------------------------------Detil jawabanKelas: 10
Mapel: Matematika
Bab: Trigonometri
Kode: 10.2.7
Kata kunci: pembuktian, penjumlahan, sinus, kosinus
15. 1.Bentuk sederhana dari : sin^2 x/1-Cos x =... 2. Sin x =2/3 , maka nilai dari sin x/1-Cos + sin x/1+cos x =...
1] (sin² x)/(1 - cos x)
= (1 - cos² x)/(1 - cos x)
= ((1 - cos x) (1 + cos x)) / (1 - cos x)
= 1 + cos x
= cos x + 1
2] sin x = 2/3
(sin x)/(1 - cos x) + (sin x)/(1 + cos x)
= (sin x + sin x cos x + sin x - sin x cos x) / (1 - cos² x)
= (2 sin x)/sin² x
= (2 sin x) / (sin x . sin x)
= 2 / sin x
= 2 / (2/3)
= 2 . 3/2
= 3
Kelas 10 Matematika
Bab Trigonometri
#backtoschoolcampaign
16. 1. 1 + cos x / sin x = 2. 1 + tan^2 A = x maka sec^2 A = 3. jika sin ∅ + cos ∅ = p maka 2 sin ∅ cos ∅ = . . .
Sifat.sin^2 x + cos^2 x = 1
.
1 + (cos x / sin x) = 1 + cot x
.
1 + tan^2 A = x
1 + (sin^2 A / cos^2 A) = x
(cos^2 A / cos^2 A) + (sin^2 A / cos^2 A) = x
(cos^2 A + sin^2 A) / cos^2 A = x
1 / cos^2 A = x
sec^2 A = x
.
sin x + cos x = p
(sin x + cos x)^2 = p^2
sin^2 x + cos^2 + 2 sin x cos x = p^2
1 + 2 sin x cos x = p^2
2 sin x cos x = p^2 - 1
.
#MathIsBeautiful
17. 1.) cos 2/3Ī . cos 1/3Ī - sin 2/3Ī . sin 1/3Ī 2.) sin²70° + cos²70°3.) 1-2 (sin 15°) ²Help me please
1.)
cos⅔Ļ . cos⅓Ļ - sin⅔Ļ . sin⅓Ļ
menggunakan rumus
cosx . cosy - sinx . siny = cos(x + y)
maka
cos⅔Ļ . cos⅓Ļ - sin⅔Ļ . sin⅓Ļ = cos(⅔Ļ + ⅓Ļ) = cosĻ = -1
2.)
sin²70° + cos²70°
menggunakan rumus
sin²x + cos²x = 1
maka
sin²70° + cos²70° = 1
3.)
1 - 2sin²15°
menggunakan rumus
1 - 2sin²x = cos2x
maka
1 - 2sin²15° = cos2(15°) = cos30° = ½√3
18. Diketahui: cos= 1 per 2 √3 Sin= 1 per 2 Carilah: cos pangkat 2 + sin
cos²+sin=(1/2 √3)² + 1/2 =1/4×3+1/2= 3/4+1/2=3/4+2/4=5/4
19. 1. Sin 30° cos 60° + cos 30° sin 60° 2. Sin²45° 3. Sin²30° -1 + cos 120°
Jawaban & Pembahasan1. sin 30° cos 60° + cos 30° sin 60°
cos 60° = sin 30°
cos 30° = sin 60°
= sin 30° sin 30° + sin 60° sin 60°
= sin² (30°) + sin² (60°)
= (½)² + (½√3)²
= ¼ + ¾
= 1
2. sin² 45°= (½√2)²
= ½
3. Sin²30° -1 + cos 120°cos (90 + 30)° = -sin 30°
= sin² 30° -1 -sin 30°
= (½)² -1 - ½
= ¼ -3/2
= -5/4
============================================
Pelajari lebih lanjutContoh soal trigonometri (kuadran) :
brainly.co.id/tugas/15684395
brainly.co.id/tugas/21854026
Contoh soal trigonometri (perjumlahan perbandingan sudut) :
brainly.co.id/tugas/9767824
brainly.co.id/tugas/9665200
============================================
Detail JawabanKelas : 10
Mapel : Matematika
Materi : Bab 7 - Trigonometri
Kode : 10.2.7
20. 1) sin 30° • cos 45° • tan 60°=2) sin 30° • cos 60° + cos 45°=3) sin 60° • cos 60° + sin 30° • cos 30°=dijadikan trigonometri menjadi:1) 1/2 • 1/2 + 1/2√31) 1/2 • 1/2 + 1/2√23) 1/2√3 • 1/2 + 1/2 • 1/2√3please bantu, sama caranya
Jawaban:
No 1
Semoga membantu ye
Penjelasan dengan langkah-langkah:
saya dah beri tinggal salin je

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