Use the Definition of Big-O to Prove That $$1 ^ { 2 } + 2 ^ { 2 } + \cdots + n ^ { 2 } \text { is } O \left( n ^ { 3 } \right)$$

Short Answer

Use the definition of big-O to prove that $$1 ^ { 2 } + 2 ^ { 2 } + \cdots + n ^ { 2 } \text { is } O \left( n ^ { 3 } \right)$$