4

I’m not sure what you want with just “4.” Do you want a quick problem set, an explanation of a concept involving the number 4, or help with a specific subject?

Here are a few quick options (you can pick one, or tell me your subject/level and I’ll tailor problems):

• Calculus: 4th derivative of x^4 is 24.
• Algebra: Solve (x − 4)(x + 2) = 0 → x = 4 or x = −2.
• Discrete math/combinatorics: How many subsets does a 4-element set have? Answer: 16.
• Probability/Statistics: If you roll a fair die, P(rolling a 4) = 1/6.
• Linear algebra: A small 4×4 matrix determinant or a 4×4 eigenvalue example (I can set up a simple one).

If you share the course and the level (e.g., intro calculus, abstract algebra, probability for statistics, etc.), I can generate a focused 4-question mini-quiz or walk you through a detailed solution.