Pertanyaan

sin 165° – cos 165° = ....

sin165° – cos165° = ....

D. Kamilia

Master Teacher

Mahasiswa/Alumni Universitas Negeri Malang

Jawaban terverifikasi

Pembahasan

Perhatikan bahwa Ingar bahwa cos 90°+ x = – sin x. Sehingga : Ingat bahwa sin ( 180°– x) = sin x. Sehingga :

Perhatikan bahwa

Ingar bahwa cos 90°+ x = – sin x. Sehingga :

$begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell sin invisible function application 165 degree minus cos invisible function application 165 degree end cell equals cell sin invisible function application 165 degree minus cos invisible function application left parenthesis 90 degree plus 75 degree right parenthesis space end cell row blank equals cell sin invisible function application 165 degree minus left parenthesis negative sin invisible function application 75 degree space right parenthesis space end cell row blank equals cell sin invisible function application 165 degree plus sin invisible function application 75 degree end cell row blank equals cell 2 space sin invisible function application open parentheses fraction numerator 165 degree plus 75 degree over denominator 2 end fraction close parentheses space cos invisible function application open parentheses fraction numerator 165 degree minus 75 degree over denominator 2 end fraction close parentheses end cell row blank equals cell 2 space sin invisible function application open parentheses fraction numerator 240 degree over denominator 2 end fraction close parentheses space space cos invisible function application open parentheses fraction numerator 90 degree over denominator 2 end fraction close parentheses end cell row blank equals cell 2 space sin invisible function application 120 degree space space cos invisible function application 45 degree end cell row blank equals cell 2 space sin invisible function application left parenthesis 180 degree minus 60 degree right parenthesis space space cos invisible function application 45 degree end cell end table end style$

Ingat bahwa sin (180°– x) = sin x. Sehingga :