Correction :
Exercice1:
2
f (x) 2x
x 1
2 2
Df x / x 1 0 x / x 1 x / x1 et x 1 1;1 4
3
f (x) 4
3
2 2 2
2
2x 4
6x 4x 4 4x 6x 4 0 2x 3x 2 0
x 1 3
25 4
3
3 5 1
x 4 2
3 5
x 2
4
f
D 1;1
2 2
2x 2x
f ( x) f (x)
( x) 1 x 1
2 2
( x) x
Df
2 2
2 2 2 2 2 2
2x 2y
f (x) f (y) x 1 y 1 2x(y 1) 2y(x 1) 2xy(x y) 2(x y) 2xy 2
T x y x y (x 1)(y 1)(x y) (x 1)(y 1)(x y) (x 1)(y 1)
0;1 0 x 1 0 y 1 1 y2 1 0 1 x2 1 0
4 2xy 2 2
T0 0;1
1; 1x 1y x2 1 0 y2 1 0 2xy 2 4
T0 1;
1; ;1
0;1 1;0
Exercice2 :
f (x) x x 2 x 2
Df
f ( x) x x 2 x 2 x x 2 x 2 (x x 2 x 2 ) f(x)
x 2 x 2
x 2 x 2
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prof: atmani najib
prof: atmani najib
f (x) x 4 si x 2 f (x) x si 2 x 2 f (x) x 4 si 2 x
; 2 Cf y x 4
2; 2 Cf y x
2; Cf y x 4
; 2
2;
http:// xyzmath.e-monsite.com
prof: atmani najib
Exercice3:
f (x) x2 4x 5 g(x) x 3 x 2
Dg
x 3 y 3
g(x) g(y) x 2 y 2 ( x 3)(y 2) ( y 3)(x 2) x y 1
T x y x y (x 2)(y 2)(x y) (x 2)(y 2)(x y) (x 2)(y 2)
; 2 x2 y2 x 2 0 y 2 0 TO
; 2
2; x2 y2 x 2 0 y 2 0 TO
2;
Cg (2; 1) x2 y 1
f (x)
2 2 2 2
f (x) x 4x 5 (x 4x 5) (x 4x 4 1) (x 2) 1 (x 2)2 0
(x 2)2 1 1 f (x) 1 f (2) 1
Cf (2; 1)
Cf
http:// xyzmath.e-monsite.com
prof: atmani najib
Cf Cg
f (x)g(x)
Cf Cg
S ;1 2;
http:// xyzmath.e-monsite.com
prof: atmani najib