Thank you for reporting, we will resolve it shortly
Q.
If $x^2+y^2=1$, then the point $P\left(x, y, \sqrt{1-x^2-y^2}\right)$ is at a distance of ...A ... units from the origin. Here, A refers to
Introduction to Three Dimensional Geometry
Solution:
The coordinates of point $P$ are $\left(x, y, \sqrt{1-x^2-y^2}\right)$.
Then,
$O P =\sqrt{(x-0)^2+(y-0)^2+\left(\sqrt{1-x^2-y^2}-0\right)^2} $
$ =\sqrt{x^2+y^2+1-x^2-y^2}=\sqrt{1}=1$