Nilai dari 4 cos 75 ? - Universityku

Nilai dari 4 cos 75 ?

4 * cos 75
= 4 * ( cos(45+30) )
= 4 * (cos 45 * cos 30 – sin 45 * sin 30)
= 4 * (√2/2 . √3/2 – √2/2 . 1/2)
= 4 * (√6/4 – √2/4)
= 4 * ((√6 – √2) / 4 )
= √6 – √2

cos 75 = $frac{ sqrt{6} -sqrt{2} }{4}$

4 . cos 75 = 4. $frac{ sqrt{6} -sqrt{2} }{4}$
= $sqrt{6}- sqrt{2}$

dalam kalimat:
4 dikali cos 75 = 4 dikali akar(6) – akar(2) per (4)
= akar(6) – akar(2)
selesai.