3D Coordinate System

• Description of 3D space – analogous to 2D
• 3D space: ${\mathbb{R}}^3$, 2D space: ${\mathbb{R}}^2$

• Distance between 2 points: $d(P_1,P_2)=\sqrt{(x_2-x_1{)}^2+(y_2-y_1{)}^2+(z_2-z1{)}^2}$
• Equation for a sphere: $(x-h{)}^2+(y-k{)}^2+(z-l{)}^2=r^2$