1 years, 15 days

## Get error...

Now, I compile with Maple 2023, I get the massage:

## Thank you very much....

@nm Thank you very much.

## Yes. Thank you very much....

@Carl Love Yes. Thank you very much.

@Carl Love I use geom3d to check points in my list. Can you add your code to check a point on the sphere?

## Thank you very much....

@Carl Love Thank you very much.

## I don't see onobjl key...

@mmcdara The question from me.  I don't see onobjl key (I use Maple 2022).

## I know how to write the equation of the ...

@Rouben Rostamian  I know how to write the equation of the tangent plane to a sphere at a given point. Let T is center of sphere and P is a point lion the sphere. The tangent plane to a sphere at the point A take vector TA = (n1, n2,n3) as normal vector. Therefore, the equation of the plane is
n1*(x-xA) + n2*(y-yA) + n3*(z-zA) = 0, It means TA  dot  (M- A) = 0, where M = (x,y,z). In my code, I use geom3d package.

With a single point, I tried
restart;
with(geom3d);
sphere(S, (x - 1)^2 + (y - 3)^2 + (z - 5)^2 - 169 = 0, [x, y, z], 'centername' = T);
point(A, -11, -1, 8);
IsOnObject(A, S);
line(d, [T, A]);
n := ParallelVector(d);
Equation(plane(P, [A, n], [x, y, z]));
expr := sort(primpart(lhs(Equation(P))));
expr*signum(lcoeff(expr)) = 0;

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