Tentukan nilai dari: - Universityku

A) 6 cos 105° sin 15°
B) -4 cos 217, 5° cos 7, 5°
C) – 1/2 sin 15° sin 45°

Tentukan nilai dari:

Penjelasan dengan langkah-langkah:

$6 cos(105) sin(15) = 6( frac{1}{2} )( sin(105 + 15) - sin(105 - 15) ) \ = 3 (sin(120) - sin(90) ) \ = 3( frac{1}{2} sqrt{3} - 1)$

$- 4 cos(217.5) cos(7.5) \ = - 4( frac{1}{2} )( cos(217.5 - 7.5) + cos(217.5 + 7.5) \ = - 2( cos(210) + cos(225) ) \ = - 2( - frac{1}{2} sqrt{3} - frac{1}{2} sqrt{2} ) \ = sqrt{3} + sqrt{2}$

$- frac{1}{2} sin(15) sin(45) \ = - frac{1}{2} ( frac{1}{2} )( cos(45 - 15) - cos(45 + 15) ) \ = - frac{1}{4} ( cos(30) - cos(60) ) \ = - frac{1}{4} ( frac{1}{2} sqrt{3} - frac{1}{2} ) \ = - frac{1}{8} ( sqrt{3} - 1)$