The “lead” in a lead pencil is actually made mostly of what form of carbon

In what direction does an applied force move an object

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of

Suppose that f : rn → rm and that a ∈ k, where k is a connected subset of rn . suppose further that for each x ∈ k there exists a δx > 0 such that f(x) = f(y) for all y ∈ bδx (x). prove that f is constant on k; that is, f(x) = f(a) for all x ∈ k