(%i1)

x : matrix( [cos(t)^2/(sx^2) + sin(t)^2/(sy^2),-sin(2*t)/(2*sx^2) + sin(2*t)/(2*sy^2)],   [-sin(2*t)/(2*sx^2) + sin(2*t)/(2*sy^2),sin(t)^2/(sx^2) + cos(t)^2/(sy^2)]);

(%i2)

xinv : trigsimp(trigexpand(trigreduce(invert(x))));

(%i3)

tex(matrix([sin(t)^2/sy^2+cos(t)^2/sx^2,sin(2*t)/(2*sy^2)-sin(2*t)/(2*sx^2)],[sin(2*t)/(2*sy^2)  -sin(2*t)/(2*sx^2),sin(t)^2/sx^2+cos(t)^2/sy^2]))$

(%i4)

text(xinv);

(%i5)

help text;

(%i5)

ascii(xinv);

(%i6)

;

(%i6)

xinv;

(%i7)

print(xinv);

(%i8)

display(inv);

(%i9)

display(xinv);

(%i10)

ldisplay(xinv);

(%i11)

string(xinv);

(%i12)

x;

(%i13)

set_display('ascii)$

(%i14)

xinv;

(%i15)

x;

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Created with wxMaxima.