Roboguru

Diketahui dan nilai . Nilai dari

Pertanyaan

Diketahui begin mathsize 14px style 270 degree less than a less than 360 degree end style dan nilai begin mathsize 14px style cotan space straight a equals negative 9 over 12 end style. Nilai dari begin mathsize 14px style cosec space straight alpha plus cos space straight alpha equals... end style

Pembahasan Soal:

Diketahui:

begin mathsize 14px style 270 degree less than a less than 360 degree end style artinya sudut a berada di kuadran keempat

begin mathsize 14px style cotan space straight alpha equals negative 9 over 12 comma space maka space tan space straight alpha equals negative 12 over 9 equals depan over samping end style

kita mencari terlebih dahulu sisi miring dari sudut a, dengan menggunakan pythagoras maka,

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell Sisi space miring end cell equals cell square root of depan squared plus samping squared end root end cell row cell Sisi space miring end cell equals cell square root of 9 squared plus 12 squared end root end cell row cell Sisi space miring end cell equals cell square root of 81 plus 144 end root end cell row cell Sisi space miring end cell equals cell square root of 225 end cell row cell Sisi space miring end cell equals 15 row blank blank blank end table end style

Maka,

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell Cosec space straight alpha end cell equals cell miring over depan end cell row cell Cosec space straight alpha end cell equals cell negative 15 over 12 space space end cell row blank blank cell left parenthesis cosec space padan space kuadran space ke space 4 thin space bernilai space negatif right parenthesis end cell end table end style  

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell Cos space straight alpha end cell equals cell samping over miring end cell row cell Cos space straight alpha end cell equals cell 9 over 15 space end cell row blank blank cell left parenthesis cos space pada space kuadran space 4 space bernilai space positif right parenthesis end cell end table end style 

Maka,

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell cosec space straight alpha plus cos space straight alpha end cell equals cell fraction numerator negative 15 over denominator 12 end fraction plus 9 over 15 end cell row blank equals cell fraction numerator negative 5 over denominator 4 end fraction plus 3 over 5 end cell row blank blank cell fraction numerator negative 25 plus 12 over denominator 20 end fraction end cell row blank equals cell fraction numerator negative 13 over denominator 20 end fraction end cell end table end style

Jadi, begin mathsize 14px style cosec space straight alpha plus cos space straight alpha equals negative 13 over 20 end style 

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 14 Maret 2021

RUANGGURU HQ

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

Coba GRATIS Aplikasi Ruangguru

Produk Ruangguru

Produk Lainnya

Hubungi Kami

Ikuti Kami

©2021 Ruangguru. All Rights Reserved