WHAT YOU NEED: an orange, pencil and paper. The orange should be as round as possible, so the peel represents the surface area of a sphere. STEP 2: Repeat this 3 more times. You should now have 4 ...

The Sphere function has d local minima except for the global one. It is continuous, convex and unimodal. The plot shows its two-dimensional form. The function is usually evaluated on the hypercube x i ...