Here's the question you clicked on:
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prove that sin20 sin40 sin60 sin80=3/16
What is your attempt so far?
calculator.lol dats all you need
Hint: \[sinx.\sin(60-x).(\sin60+x) = \frac{ \sin 3x }{ 4 }\]
sin60 is \[\sqrt{3}/2\] right? put it there in that, and then apply the above formula you'll get it... \[\sqrt{3}/2\] * sin60/4 = 3/2*4*2 = 3/16