MATHEMATICS · Single correct · AP · Calculus BC · Parametric, Polar, and Vector-Valued Functions · Parametric, Polar, and Vector-Valued Functions
Problem
A particle moves along the space curve r(t)=⟨(1+t)cost,(1+t)sint,t2⟩. Its velocity is v(t)=r′(t), and its angular momentum about the origin is defined as L(t)=r(t)×v(t). What is L′(t) evaluated at t=0?
(a) ⟨0,−2,0⟩
(b) ⟨0,2,−2⟩
(c) ⟨0,−2,2⟩
(d) ⟨0,0,1⟩