QuestionA norm on VV satisfies triangle inequality, scalar homogeneity, and positive-definiteness. Consider ∥(x1,x2,x3)∥=∣x1+x2+x3∣\| (x_1,x_2,x_3)\|=|x_1+x_2+x_3| on R3\mathbb{R}^3. Which conditions are satisfied?