Answer:
Equation:

Intersection:

Step-by-step explanation:
We are asked to write an equation of the sphere with center center
and radius 4.
We know that equation of a sphere with radius 'r' and center at
is in form:

Since center of the given sphere is at point
, so we will substitute
,
,
and
in above equation as:


Therefore, our required equation would be
.
To find the intersection of our sphere with the yz-plane, we will substitute
in our equation as:




Therefore, the intersection of the given sphere with the yz-plane would be
.