You mean to ask what is its equation?Originally Posted byBad Apple

In xy co-ordinate system there is the x-co-ordinate and the y-co-ordinate. Thus, there are two dimensions. When mapping a sphere you need a third dimension. When studing Multivaraible Calculus you will be introduced to 3 dimensional graphs and vectors. The third variable introduced is z. The equation of a sphere is then,

where is its radius.