Question

1. Sin 105°=
A.Sin 75°
B. Sin 65°
C. -Sin 75°
D. -Sin 65
E. Sin 55°

Tuliskan cara dan jawaban

Answer 1

1. sin (60+45) = sin60 cos45 + cos 60 sin 45
= ½√3 × ½√2 + ½ × ½√2
= ¼√6 + ¼√2
¼(√6 + √2)
¼√2(√3 + 1)
2. sin (45+30) = sin45 cos30 + cos45 sin30
= ½√2 × ½√3 + ½√2 × ½
= ¼(√6 + √2)

Answer 2

Setara sin 105 = sin (180 - 75) = sin 75