Réponse :
1- h(x) existe ssi x+5 ≥0 ⇔x≥-5
2- h(0) =√(0+5) =√5
h(20) =√(20+5) =√25 = 5
h(-4) =√(-4+5) =√1 =1
3- h(x) = -2 ⇔√(x+5) = -2 ⇔x+5 = 4 ⇔ x = -1
h(x) = 3 ⇔√(x+5) = 3 ⇔x+5 = 9 ⇔ x =4
h(x) = 2 ⇔√(x+5) = 2 ⇔x+5 = 4 ⇔ x = -1
Explications étape par étape