2. When using separate chaining, why might we encounter worst-case O(n) insertion instead of just O(1)? . When using separate chaining, would you insert new elements at the head or tail of the linked lists? Why? 4. When using quadratic probing, we stop and expand the hash table dynamically if it ever becomes half full. When we do so, we must re-insert each element using our hash function. Why can't we just copy the elements from the old array into the same indices in the new array