1. Using Scheme as a desk calculator, determine the arithmetic mean of the numbers 74, 81, 87, and 90.
2. Give a Scheme expression of which the value is a four-element list with
the number 7 as its first element, the symbol a the second,
the number -12 the third, and the symbol ??? the fourth.
3. Give a Scheme expression of which the value is a three-element list with
the symbol * as its first element and the number
-5 as its second and third.
4. Give a Scheme expression that, when evaluated, determines whether the
first element of the three-element list mentioned in the previous exercise
is a symbol. (The result of the evaluation should be #t.)
5. Give a Scheme expression of which the value is a two-element list with the empty list as its first and second element.
6. After the definition
(define dozen 12)what will be the value of the Scheme expression
(number?
dozen)?
7. Give a Scheme definition that will determine the sum of 31, 29, 31, 30,
31, and 10 and bind the identifier day-of-year to this
sum.
8. Define a Scheme procedure square that, given any number as
an argument, returns the square of that number.
9. Define a recursive Scheme procedure first-symbol that finds
and returns the first element of a given list that is a symbol (but returns
#f if none of the elements of the list is a symbol).
10. Define a recursive Scheme procedure add-1-to-each that,
given any list of numbers, returns a list of equal length in which each
element is 1 greater than the corresponding element of the given list.
For example, the value of (add-1-to-each '(3 8 6)) should
be (4 9 5).
11. Define a recursive Scheme procedure tally that counts and
returns the number of occurrences of a given value in a given list. For
example, the value of (tally 'a '(b a 7 c a a 3 a)) should be
4.
12. Define a Scheme procedure all-different? that determines
whether all of the top-level elements of a given list are distinct (that
is, not equal?).
I'll also be happy to discuss any of the exercises from chapters 1 and 2 of the text.