How can I solve Qn7(ii)? I am abit confused with the solution provided. It stated that we have to use (u^-alpha + v^-alpha + w^-alpha - 1) ^-1/alpha, and the respective values of u , v and w are 0.2134 , 0.1587 , and 0.5. However, the solution at the end become (0.2134^-2 + 0.1587^-2 + 0.5^-2 - 2)^-1/2 = 0.1253.. How did -1 in the original formula becomes -2 when values are sub in?