# 3

> restart : with(linalg):

Warning, new definition for norm

Warning, new definition for trace

> x := a* cos(t);

> y := b *sin(t) ;

> c := [x,y] ;

> intgrand := 1/2* dotprod( [ -y, x ] , [ diff(x,t) , diff(y,t) ]);

> intgrand := simplify(intgrand);

> A := int( intgrand , t = 0 .. 2*Pi);

>