## Discovering Mathematics with Maple End of Chapter 4 Problems: Additional Hints

1. This is just a case of allowing Maple to evaluate the sums, and then simplifying them.
a) [Hint: to simplify this you must use first "convert(%,factorial)", then "simplify(%)", by eye it is easy to see the cancellation which occurs among the 4 factors in factorial form.]
b) [Here simplify is enough, since the cancellation occurs outside the binomial coefficient factor, and is trivial to see: the last term in the numerator is -2 times the denominator.]

2. Fill in the discussion from the example in the section 4.2 file so that it makes a  complete report. Don't just type in the code in the back of the book, but try to set up why that then finishes off the problem.

5. This is interesting and more elementary than some of the others, following up on a problem already begun in a preliminary worksheet.

6. This is the 2d random walk problem: http://en.wikipedia.org/wiki/Random_walk .
Understand and explain the code given in the back of the book.

7. This is straightforward following the similar example in the chapter, using linear algebra to find the coefficients in the 2nd order recursion relation.

8. Again relatively straightforward following up examples with rand() in a preliminary worksheet.