Exercise 1.15)

(define (cube x) (* x x x))
(define (p x) (- (* 3 x) (* 4 (cube x))))
(define (sine angle)
   (if (not (> (abs angle) 0.1))
       angle
       (p (sine (/ angle 3.0)))))

a.  How many times is the procedure p applied when (sine 12.15) is evaluated?

5 times.

sine is called with the following arguments:
12.15
4.05
1.35
0.45
0.15
0.05

All but the last of these call p.

b.  What is the order of growth in space and number of steps (as a function of 
    a) used by the process generated by the sine procedure when (sine a) is 
    evaluated?

It requires ϴ(log n) space and steps.