In physics, pressure is the amount of force exerted on a surface per unit area, p = startfraction f over a endfraction the pressure, in atmospheres (atms), of a liquid on the circular base of a bucket is represented by the composite function (p ∘ a)(r), where and a(r) = πr². what is the domain of the composite function? {all real numbers} {r | r ≠0} {r | r > 0} {r | r < 0}