(a) … (b) … (c) … (d)

Which vectors follow the same path as $\mathbf{R}=t\mathbf{i}+t^2\mathbf{j}$? The speed along the path may be different.

(a) $2t\mathbf{i}+2t^2\mathbf{j}$ (b) $2t\mathbf{i}+4t^2\mathbf{j}$ (c) $-t\mathbf{i}+t^2\mathbf{j}$ (d) $t^3\mathbf{i}+t^6\mathbf{j}$

Gilbert Strang, Calculus, 3rd edition (Wellesley-Cambridge Press; MIT OpenCourseWare RES.18-001) · §12.1 The Position Vector, #16