Sagot :
Ex01:
1) a > b > 0
alors 1/b > 1/a
2) -1/2 < 1/x < -1/5
3) x > 0 ou x < -1/2
Ex02:
1) Df = ]-oo ; 1[U]1 ; +oo[
2) f(x) = (3(x-1)+2)/(x-1) = (3x-1)/(x-1)
Ex03:
1) f(x) = 3
3x-1 = 3(x-1)
-1 = -3 impossible
2) f(x) = 0
3x = 1
x = 1/3
(1/3 ; 0)
3) f(0) = -1
(0 ; -1)
Ex04:
a)
-2 3
-x+3 + + 0 -
x+2 - 0 + +
(-x+3)/(x+2) - + 0 -
solution: ]-oo ; -2[U[3 ; +oo[
b) (1-2x)/x > 0
0 1/2
x - 0 + +
1-2x + + 0 -
(1-2x)/x - + 0 -
solution: ]0 ; 1/2[