Pertanyaan

Nilai cos 30 0 ∘ + 2 cos 24 0 ∘ − sin 21 0 ∘ adalah...

Nilai $cos 30 0^{\circ} + 2 cos 24 0^{\circ} - sin 21 0^{\circ}$ adalah...

S. Nur

Master Teacher

Jawaban terverifikasi

Pembahasan

Dengan menggunakan konsep trigonometri, nilai adalah Jadi,

Dengan menggunakan konsep trigonometri, nilai cos space 300 degree plus 2 space cos space 240 degree minus sin space 210 degree adalah

table attributes columnalign right center left columnspacing 0px end attributes row cell cos space 300 degree end cell equals cell cos left parenthesis 360 degree minus 300 degree right parenthesis end cell row blank equals cell cos space 60 degree end cell row blank equals cell 1 half end cell end table

table attributes columnalign right center left columnspacing 0px end attributes row cell cos space 240 degree end cell equals cell cos left parenthesis 180 degree plus 60 degree right parenthesis end cell row blank equals cell negative cos space 60 degree end cell row blank equals cell negative 1 half end cell end table

table attributes columnalign right center left columnspacing 0px end attributes row cell sin space 210 degree end cell equals cell sin space left parenthesis 180 degree plus 30 degree right parenthesis end cell row blank equals cell negative sin space 30 degree end cell row blank equals cell negative 1 half end cell end table

Jadi,

$table attributes columnalign right center left columnspacing 0px end attributes row cell cos space 300 degree plus 2 space cos space 240 degree minus sin space 210 degree end cell equals cell 1 half plus 2 cross times fraction numerator negative 1 over denominator 2 end fraction minus fraction numerator negative 1 over denominator 2 end fraction end cell row blank equals cell 1 half minus 1 plus 1 half end cell row blank equals 0 end table$