prob11-2-24.mws

> f1 := 1/( 1 - x^2 -y^2 );

f1 := 1/(1-x^2-y^2)

> with(plots);

> plot3d(f1, x=-2.0..2.0, y=-2.0..2.0);

[Maple Plot]

> plot3d(f1, x=-2.0..2.0, y=-2.0..2.0);

[Maple Plot]

> y1 := (1-x^2)^(1/2);

y1 := sqrt(1-x^2)

> plot(y1, x =-2.0..2.0);

[Maple Plot]