Roboguru

Diketahui , dengan  maka nilai

Pertanyaan

Diketahui tan space straight A equals negative 1 half, dengan straight pi over 2 less than straight A less than straight pi maka nilai sin space straight A times cos space straight A equals....  

Pembahasan Soal:

Diketahui tan space straight A equals negative 1 half,

Misalkan: tan space straight A equals y over x, sehingga

table attributes columnalign right center left columnspacing 0px end attributes row r equals cell square root of x squared plus y squared end root end cell row blank equals cell square root of open parentheses negative 1 close parentheses squared plus 2 squared end root end cell row blank equals cell square root of 1 plus 4 end root end cell row blank equals cell square root of 5 end cell end table 

dengan straight pi over 2 less than straight A less than straight pi artinya sudut A berada diantara 90 degree dan 180 degree atau sudut A berada di kuadran II.

  • sin di kuadran II bernilai positif

sin space straight A equals y over r equals fraction numerator 1 over denominator square root of 5 end fraction 

  • cos di kuadran II bernilai negatif

cos space straight A equals x over r equals negative fraction numerator 2 over denominator square root of 5 end fraction 

Maka,

 table attributes columnalign right center left columnspacing 0px end attributes row cell sin space straight A times cos space straight A end cell equals cell fraction numerator 1 over denominator square root of 5 end fraction times open parentheses negative fraction numerator 2 over denominator square root of 5 end fraction close parentheses end cell row blank equals cell negative 2 over 5 end cell end table 

Jadi, nilai sin space straight A times cos space straight A equals negative 2 over 5.  

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 03 Juni 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