If $\vec{x}, \vec{y} \in \mathbb{R}^n$. Is it always true that $ \|\vec{x} + \vec{y}\| \geq \|\vec{x}\| - \|\vec{y}\| $ ?
Any advice or proofs would be greatly appreciated.
If $\vec{x}, \vec{y} \in \mathbb{R}^n$. Is it always true that $ \|\vec{x} + \vec{y}\| \geq \|\vec{x}\| - \|\vec{y}\| $ ?
Any advice or proofs would be greatly appreciated.