integrate(sin(x)*cos(x),x)



On Tue, 2007-05-15 at 20:23 -0500, Doug Stewart wrote:
> I was showing my students how to use Maxima to check their homework.
> 
> When I got to this part of the example I got a surprise.
> integrate(sin(x)*cos(x),x)
> 
> maxima said it was  -cos^2(x)/2  and my book said it was sin^2(x)/2 so I 
> looked it up in shaums formula book
> and it said sin^2(x)/2.
> 
> So I then plotted up a graph in Octave and was convinced that Maxima is 
> wrong.
> 
> I then submitted a bug report and someone replied and told me that I 

You don't even need calculus -- sin^2(x) + cos^2(x) = 1 is a trig
identity.  That still doesn't justify rudeness.  The fact that this is a
well-known identity does not imply that someone will see how to apply it
in just the right form in a particular situation.