Question

Tentukan sin 75 x 1/4 akar2 (1+akar3) adalah

Answer 1

Sin 75 x ¹/₄√2 (1 + √3) = ..
= sin(45+30)   (¹/₄ √2 + ¹/₄√6)
= (sin 45 cos 30 + cos 45 sin 30 )(¹/₄√2+ ¹/₄ √6)
= {(¹/₂ √2 )(¹/₂√3) +(¹/₂ √2 . ¹/₂)} (¹/₄√2 + ¹/₄√6)
= {(¹/₄ √6 )+(¹/₄√2 )}(¹/₄√2 + ¹/₄√6)
= (¹/₄√6 + ¹/₄√2)²
= ¹/₂ +¹/₄√3
= ¹/₄ ( 2 + √3)