Iklan

Pertanyaan

Diketahui sudut antara vektor a dan b adalah 6 0 ∘ . Jika a ⋅ a = 9 dan a → ⋅ b → = 18 maka b → ⋅ ( a + b ) = . . . .

Diketahui sudut antara vektor  dan  adalah . Jika  dan  maka  

  1. undefined150

  2. undefined125

  3. 90undefined 

  4. 162undefined 

  5. 183undefined 

Ikuti Tryout SNBT & Menangkan E-Wallet 100rb

Habis dalam

00

:

01

:

29

:

34

Klaim

Iklan

P. Anggrayni

Master Teacher

Jawaban terverifikasi

Jawaban

jawaban yang tepat adalah D.

jawaban yang tepat adalah D.

Pembahasan

Karena , maka Karena panjang vektor tidak mungkin negatif, maka Kemudian sudut antara vektor dan adalah . Sehingga Sehingga Dengan demikian, jawaban yang tepat adalah D.

Karena begin mathsize 14px style a with rightwards arrow on top times a with rightwards arrow on top equals 9 end style, maka

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell a with rightwards arrow on top times a with rightwards arrow on top end cell equals 9 row cell vertical line a with rightwards arrow on top vertical line squared end cell equals 9 row cell vertical line a with rightwards arrow on top vertical line end cell equals cell plus-or-minus square root of 9 end cell end table end style 

Karena panjang vektor tidak mungkin negatif, maka begin mathsize 14px style open vertical bar a with rightwards arrow on top close vertical bar equals square root of 9 equals 3 end style 

Kemudian sudut antara vektor undefined dan undefined adalah undefined. Sehingga

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell a with rightwards arrow on top times b with rightwards arrow on top end cell equals cell vertical line a with rightwards arrow on top vertical line vertical line b with rightwards arrow on top vertical line cos space 60 degree end cell row 18 equals cell 3 times vertical line b with rightwards arrow on top vertical line times 1 half end cell row 18 equals cell 3 over 2 times vertical line b with rightwards arrow on top vertical line end cell row cell vertical line b with rightwards arrow on top vertical line end cell equals cell 36 over 3 end cell row cell vertical line b with rightwards arrow on top vertical line end cell equals 12 end table end style 

Sehingga

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell b with rightwards arrow on top times open parentheses a with rightwards arrow on top minus b with rightwards arrow on top close parentheses end cell equals cell b with rightwards arrow on top times a with rightwards arrow on top plus b with rightwards arrow on top times b with rightwards arrow on top end cell row blank equals cell a with rightwards arrow on top times b with rightwards arrow on top plus open vertical bar b with rightwards arrow on top close vertical bar squared end cell row blank equals cell 18 plus open parentheses 12 close parentheses squared end cell row blank equals cell 18 plus 144 end cell row blank equals 162 end table end style 

Dengan demikian, jawaban yang tepat adalah D.

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

1

Iklan

Pertanyaan serupa

Jika vektor v dan vektor u membentuk sudut 6 0 ∘ , dimana u = 4 dan v = 2 maka u ( v + u ) = ....

1

4.9

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

©2025 Ruangguru. All Rights Reserved PT. Ruang Raya Indonesia