#lang racket
(define x 5)
(define (f x ) (* x x ))

(define d 1)
(define (plusd x) ( + x d))

(set! d 5)

(define (g x ) (+ 1 (h x)))
(define (h x) (* x x))

(define monabs ( lambda (x) (sqrt (* x x))))
(define care-div ( lambda (x y) (if (not ( = 0 y)) (/ x y) ( display "Err div 0"))))
(define exo9 (lambda (t) (if (and ( >= t -3) (<= t -1)) 1 (if (and (>= t 2) (<= t 4)) 2 0))))
(define placement (lambda (x t y) (expt (+ x (* t x)) y )))