Question

Soal Matematika digambar:
Terimakasih

Answer 1

a. Sin 15° cos 15°

sin a cos a = 1/2 ( sin (a+a) + sin (a-a) )

sin 15° cos 15° = 1/2 ( sin 30° + sin 0° )

sin 15° cos 15° = 1/2 ( 1/2 + 0 )

Sin 15° cos 15° = 1/4

b. Cos π/12 - cos5π/12

cos π/12 - cos 5π/12 = -2 sin 45° sin 30°

= -2 1/2√2 • 1/2

= -√2/2