Bjr,
Ex. 42 :
1) f(x) = x(x+3)
2)
a) f(-3) = -3(-3+3) = -3(0) = 0 VRAI
b) f(7) = 7(7+3) = 70 VRAI
c) f(2) = 2(2+3) = 10 FAUX
d) f(-4) = -4(-4+3) = 4 VRAI
Ex. 43 :
1)
a) 2² = 4
4 × 5 = 20
20 + 10 = 30
VRAI
b) 0,1² = 0,01
0,01 × 5 = 0,05
0,05 + 10 = 10,05
2)
a) p(x) = 5x² + 10
b) p(-1) = 5(-1²) + 10 = 5 + 10 = 15
p(3) = 5(3²) + 10 = 5×9 + 10 = 55
p(0) = 5(0²) + 10 = 10
c) p(0,2) = 5(0,2²) + 10 = 5×0,04 + 10 = 0,2 + 10 = 10,2
