Exercise 1.40. Define a procedure `cubic`

that can be used together
with the newtons-method procedure in expressions of the form

(newtons-method (cubic a b c) 1)

to approximate zeros of the cubic .

Exercise 1.41. Define a procedure `double`

that takes a procedure of
one argument as argument and returns a procedure that applies the
original procedure twice.
For example, if `inc`

is a procedure that
adds 1 to its argument, then `(double inc)`

should be a procedure that
adds 2. What value is returned by

(((double (double double)) inc) 5)

Exercise 1.42. Let `f`

and `g`

be two one-argument functions. The
composition `f`

after `g`

is defined to be the function
.
Define a procedure `compose`

that implements composition.
For example, if `inc`

is a procedure that adds 1 to its argument,

((compose square inc) 6)

2002-04-11