📑 Sommaire
Quiz – Calcule de a et calcule de b ≡
📘 Trouver a
1) On a : \( f(1)=3 \) et \( f(3)=7 \)
Afficher correction
Étape :
\( a = \dfrac{3 – 7}{1 – 3} = \dfrac{-4}{-2} = 2 \)
✔ \( a = 2 \)
2) On a : \( f(2)=2 \) et \( f(4)=0 \)
Afficher correction
\( a = \dfrac{2 – 0}{2 – 4} = \dfrac{2}{-2} = -1 \)
✔ \( a = -1 \)
3) On a : \( f(2)=4 \) et \( f(4)=10 \)
Afficher correction
\( a = \dfrac{4 – 10}{2 – 4} = \dfrac{-6}{-2} = 3 \)
✔ \( a = 3 \)
📗 Trouver l’expression de f
1) On a : \( f(1)=3 \) et \( f(3)=7 \)
Afficher correction
Étape 1 :
\( a = 2 \)
Étape 2 :
\( 3 = 2 \times 1 + b \Rightarrow b = 1 \)
✔ \( f(x) = 2x + 1 \)
2) On a : \( f(2)=2 \) et \( f(4)=0 \)
Afficher correction
\( a = -1 \)
\( 2 = -1 \times 2 + b \Rightarrow b = 4 \)
✔ \( f(x) = -x + 4 \)
3) On a : \( f(2)=4 \) et \( f(4)=10 \)
Afficher correction
\( a = 3 \)
\( 4 = 3 \times 2 + b \Rightarrow b = -2 \)
✔ \( f(x) = 3x – 2 \)