Pertanyaan

[UN 2013 IPA] Nilai dari sin 11 5 ∘ + sin 5 ∘ cos 11 5 ∘ + cos 5 ∘ adalah …

[UN 2013 IPA]

Nilai dari $\frac{cos 11 5 ^{\circ} + cos 5 ^{\circ}}{sin 11 5 ^{\circ} + sin 5 ^{\circ}}$ adalah …

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A. Nadhira

Master Teacher

Mahasiswa/Alumni Universitas Negeri Malang

Jawaban terverifikasi

Pembahasan

$fraction numerator cos space 115 degree plus cos space 5 degree over denominator sin space 115 degree space plus sin space 5 degree end fraction$

$equals fraction numerator 2 space cos begin display style 1 half end style left parenthesis 115 plus 5 right parenthesis degree space cos begin display style 1 half end style left parenthesis 115 minus 5 right parenthesis degree over denominator 2 space sin begin display style 1 half end style left parenthesis 115 plus 5 right parenthesis degree space cos begin display style 1 half end style open parentheses 115 minus 5 close parentheses degree end fraction equals fraction numerator up diagonal strike 2 space cos space 60 degree. up diagonal strike space cos space 55 degree end strike over denominator up diagonal strike 2 space sin space 60 degree. up diagonal strike space cos space 55 degree end strike end fraction equals text cot end text space 60 degree equals 1 third square root of 3$