Physics

Problem

Which one of the following correctly represents the position vector

\mathbf r

of a point whose Cartesian coordinates are

(x,y)

? a)

y\,\hat{\mathbf i}+x\,\hat{\mathbf j}

x\,\hat{\mathbf i}+y\,\hat{\mathbf j}

(x+y)\,\hat{\mathbf k}

x\,\hat{\mathbf j}+y\,\hat{\mathbf i}