Question 5 When a riskless asset is available, there is a change in our contraints. Let wo be the weight on riskfree asset. Using wo=1 Wi-...-wn, we have (Ei - rf)wi + (E2 - rf)w2+...+(En -rf)wn = u-rf , expressed in excess return forms. Our problem is to solve% min. w'Ew subject to w'(E r:1) = urf {w} Note that our objective function w'Xw is still the same because the covariances with riskfree asset are all zero and we can still stick to (N