Iklan

Pertanyaan

Diketahui vektor a = ⎝ ⎛ ​ x 1 2 ​ ⎠ ⎞ ​ dan b = ⎝ ⎛ ​ 2 3 − 1 ​ ⎠ ⎞ ​ dan panjang proyeksi vektor a pada vektor b adalah 7 1 ​ 14 ​ . Sudut antara dan adalah α , maka cos α = ...

Diketahui vektor  dan  dan panjang proyeksi vektor  pada vektor  adalah . Sudut antara stack text a end text with rightwards arrow on top dan stack text b end text with rightwards arrow on top adalah , maka  

  1. 1 over 7 square root of 7 

  2. 1 over 14 square root of 14 

  3. 1 over 21 square root of 21 

  4. 1 over 27 square root of 27 

  5. 1 over 28 square root of 28 

Ikuti Tryout SNBT & Menangkan E-Wallet 100rb

Habis dalam

02

:

08

:

26

:

49

Klaim

Iklan

H. Eka

Master Teacher

Mahasiswa/Alumni Universitas Pendidikan Indonesia

Jawaban terverifikasi

Jawaban

tidak terdapat pilihanjawaban yang tepat.

tidak terdapat pilihan jawaban yang tepat.

Pembahasan

Panjang vektor , yaitu Jika vektor dan , maka Jika vektor pada vektor membentuk sudut , maka berlaku: Panjang proyeksi vektor pada vektor dapat ditentukan menggunakan rumus berikut. Berdasarkan konsep di atas, nilai dapat ditentukansebagai berikut. Diperoleh sehingga Nilai adalah sebagai berikut. Oleh karena itu, tidak terdapat pilihanjawaban yang tepat.

Panjang vektor a with rightwards arrow on top equals x i with rightwards arrow on top plus y j with rightwards arrow on top plus z k with rightwards arrow on top, yaitu open vertical bar a with rightwards arrow on top close vertical bar equals square root of x squared plus y squared plus z squared end root

Jika vektor a with rightwards arrow on top equals a subscript 1 i with rightwards arrow on top plus a subscript 2 j with rightwards arrow on top plus a subscript 3 k with rightwards arrow on top dan b with rightwards arrow on top equals b subscript 1 i with rightwards arrow on top plus b subscript 2 j with rightwards arrow on top plus b subscript 3 k with rightwards arrow on top, maka

a with rightwards arrow on top times b with rightwards arrow on top equals a subscript 1 times b subscript 1 plus a subscript 2 times b subscript 2 plus a subscript 3 times b subscript 3

Jika vektor a with rightwards arrow on top pada vektor b with rightwards arrow on top membentuk sudut alpha, maka berlaku:

a with rightwards arrow on top times b with rightwards arrow on top equals open vertical bar a with rightwards arrow on top close vertical bar open vertical bar b with rightwards arrow on top close vertical bar space cos space alpha

Panjang proyeksi vektor a with rightwards arrow on top pada vektor b with rightwards arrow on top dapat ditentukan menggunakan rumus berikut.

open vertical bar c with rightwards arrow on top close vertical bar equals fraction numerator a with rightwards arrow on top times b with rightwards arrow on top over denominator open vertical bar b with rightwards arrow on top close vertical bar end fraction

Berdasarkan konsep di atas, nilai x dapat ditentukan sebagai berikut.

table attributes columnalign right center left columnspacing 0px end attributes row cell open vertical bar c with rightwards arrow on top close vertical bar end cell equals cell fraction numerator a with rightwards arrow on top times b with rightwards arrow on top over denominator open vertical bar b with rightwards arrow on top close vertical bar end fraction end cell row cell 1 over 7 square root of 14 end cell equals cell fraction numerator open parentheses table row x row 1 row 2 end table close parentheses open parentheses table row 2 row 3 row cell negative 1 end cell end table close parentheses over denominator square root of 2 squared plus 3 squared plus open parentheses negative 1 close parentheses squared end root end fraction end cell row cell 1 over 7 square root of 14 end cell equals cell fraction numerator 2 x plus 1 times 3 plus 2 open parentheses negative 1 close parentheses over denominator square root of 4 plus 9 plus 1 end root end fraction end cell row cell 1 over 7 square root of 14 end cell equals cell fraction numerator 2 x plus 1 over denominator square root of 14 end fraction end cell row cell 1 over 7 square root of 14 times square root of 14 end cell equals cell 2 x plus 1 end cell row cell 14 over 7 end cell equals cell 2 x plus 1 end cell row 2 equals cell 2 x plus 1 end cell row cell 2 x end cell equals 1 row x equals cell 1 half end cell end table

Diperoleh x equals 1 half sehingga a with rightwards arrow on top equals open parentheses table row cell 1 half end cell row 1 row 2 end table close parentheses

Nilai cos space alpha adalah sebagai berikut.

table attributes columnalign right center left columnspacing 0px end attributes row cell cos space alpha end cell equals cell fraction numerator a with rightwards arrow on top times b with rightwards arrow on top over denominator open vertical bar a with rightwards arrow on top close vertical bar open vertical bar b with rightwards arrow on top close vertical bar end fraction end cell row blank equals cell fraction numerator 1 over denominator open vertical bar a with rightwards arrow on top close vertical bar end fraction times fraction numerator a with rightwards arrow on top times b with rightwards arrow on top over denominator open vertical bar b with rightwards arrow on top close vertical bar end fraction end cell row blank equals cell fraction numerator 1 over denominator square root of open parentheses begin display style 1 half end style close parentheses squared plus 1 squared plus 2 squared end root end fraction times 1 over 7 square root of 14 end cell row blank equals cell fraction numerator 1 over denominator square root of begin display style 21 over 4 end style end root end fraction times 1 over 7 square root of 14 end cell row blank equals cell fraction numerator 1 over denominator begin display style 1 half end style square root of 21 end fraction times 1 over 7 square root of 14 end cell row blank equals cell fraction numerator 2 over denominator square root of 21 end fraction times 1 over 7 square root of 14 end cell row blank equals cell 2 over 21 square root of 6 end cell end table

Oleh karena itu, tidak terdapat pilihan jawaban yang tepat.

Perdalam pemahamanmu bersama Master Teacher
di sesi Live Teaching, GRATIS!

1

Ozeus 275

Bantu banget

Iklan

Pertanyaan serupa

Diketahui titik-titik A ( 2 , 1 , − 3 ) , B ( 10 , 1 , 3 ) dan C ( 8 , 4 , − 1 ) . Jika titik D merupakan proyeksi titik C pada garis AB maka panjang AD sama dengan ...

1

4.2

Jawaban terverifikasi

RUANGGURU HQ

Jl. Dr. Saharjo No.161, Manggarai Selatan, Tebet, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta 12860

Coba GRATIS Aplikasi Roboguru

Coba GRATIS Aplikasi Ruangguru

Download di Google PlayDownload di AppstoreDownload di App Gallery

Produk Ruangguru

Hubungi Kami

Ruangguru WhatsApp

+62 815-7441-0000

Email info@ruangguru.com

[email protected]

Contact 02140008000

02140008000

Ikuti Kami

©2024 Ruangguru. All Rights Reserved PT. Ruang Raya Indonesia