Writing regular expressions describing languages of strings.

Write a regular expression describing the language of strings that have at least two 1's. The language consists of 0's and 1's.

Working with the big-Oh notation.

Why is it true that 20n^3+10n log(n)+5 is O(n^3)? What happened to the other terms? (Note: n^3 means n cubed, or n to the power of 3)

Working with set theory: subtraction, union, and intersection.

If we define the following two sets: A = {1, 2, 3, 4, 5} B = {5, 6, 7, 8, 9} What are the following: A - B? A union B? (The union of A and B) A intersect B? (The intersect of A and B)

Determining if P = NP.

If I can show that some NP-complete problem is in P, does P = NP? Why, or why not?

write a code in preparation for creating a spell-checker

Write a code in preparation for creating a spell-checker. I will provide a dictionary. For now don't worry about acutally spell checking: Just write a program that can read in the dictionary word by word. The dictionary is large, having over 125,000 words in it. Reading this in word by word will be easy, since there is one word per line. The dictionary is attached.