b. 2 cos (m + n) sin (m – n)
Jawaban:
2 sin α˚ ∙ cos β˚ = sin (α˚ + β˚) + sin (α˚ - β˚)
a. 2 sin 50˚ cos 30˚
= sin (50˚ + 30˚) + sin (50˚ - 30˚)
= sin 80˚ + sin 20˚
2 cos α˚ ∙ sin β˚ = sin (α˚ + β˚) - sin (α˚ - β˚)
b. 2 cos (m + n) sin (m – n)
= sin [(m + n) + (m – n)] – sin [(m + n) – (m – n)]
= sin (m + n + m – n) – sin (m + n – m + n)
= sin 2m – sin 2n
Penulis | : | Ratnaningtyas Winahyu |
Editor | : | Ratnaningtyas Winahyu |
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