16sin20.sin40.sin60.sin80=3 Prove.?

1 Answer
Mar 5, 2018

Explanation in below

Explanation:

x=16sin20sin40sin60sin80

=1632sin80sin40sin20

=83sin80sin40sin20

=43(cos40cos120)sin20

=43(cos40+cos60)sin20

=43cos40sin20+43cos60sin20

=23(sin60sin20)+23sin20

=23sin60

=2332

=3