cos20°cos40°cos80°=...?


Question and Answers Forum

All Questions Topic List
None Questions
Previous in All Question Next in All Question
Previous in None Next in None
Question Number 103299 by B. H 28 last updated on 14/Jul/20

$c o s 20 ° c o s 40 ° c o s 80 ° = . . . ?$
	Answered by bemath last updated on 14/Jul/20

	$\frac{1}{4} \cos 3 θ = \frac{1}{4} \times \cos 3 . 20^{o} = \frac{1}{4} \times \frac{1}{2} = \frac{1}{8}$
	Answered by Dwaipayan Shikari last updated on 14/Jul/20

	$\frac{1}{2 s i n 20 °} (s i n 40 ° c o s 40 ° c o s 80 °) = \frac{1}{4 s i n 20 °} (s i n 80 ° c o s 80 °) = \frac{s i n 160 °}{8 s i n 20 °} = \frac{1}{8}$
Terms of Service
Privacy Policy
Contact: info@tinkutara.com

Question and Answers Forum