Solution to Exercise 1.29:

`(define (sum term a next b)`

(if (> a b)

0

(+ (term a)

(sum term (next a) next b))))

```
```(define (inc n) (+ n 1))

`(define (simpsons-integral f a b n)`

(define (do-it h)

(define (y k)

(f (+ a (* k h))))

(define (simpson-term k)

(* (y k)

(cond ((or (= k 0) (= k n)) 1)

((odd? k) 4)

(else 2))))

(* (/ h 3) (sum simpson-term 0 inc n)))

(do-it (/ (- b a) n)))