.
For y = -1, - ¼, - ½, 0, ½, ¼, 1 the traces are circles:
in the planes x = k, y = k,z = k.
Then identify the surface and sketch it.
Solution: Rewrite equation as
.
For y = -1, - ¼, - ½, 0, ½, ¼, 1 the traces are circles:
Setting x = 0 gives us the equation
, whose graph is a pair of lines y = z,
y = -z in the x = 0 plane:
To continue, at z = 0 the resulting equation is
;
the traces are the lines y = x and y = -x:
Finally, assembled, we have a cone with its vertex at the origin:
by: gm