SIMBOLIC INTEGRAL: Is this a bug???



Hello,


      I found some problem when integrating:


    integrate(integrate(sqrt(4*x^2-y^2),x, y,1), y, 0,1)


   and


    integrate(integrate(sqrt(4*x^2-y^2),y,0,x),x,0,1)


Both are the same integral in a triangle {0<x<1; 0<y<x} in

different order of integration. However, the results does not

match.


Is this a bug of 'integrator', or I am doing something wrong?


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