What does cosx sinx equal?

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Answer 1 · 2016-03-07T17:19:31

$cos(x)sin(x) = sin(2x)/2$

So we have

$cos(x)sin(x)$

If we multiply it by two we have

$2cos(x)sin(x)$

Which we can say it's a sum

$cos(x)sin(x)+sin(x)cos(x)$

Which is the double angle formula of the sine

$cos(x)sin(x)+sin(x)cos(x)=sin(2x)$

But since we multiplied by 2 early on to get to that, we need to divide by two to make the equality, so

$cos(x)sin(x) = sin(2x)/2$