Bonjour,
donner les valeurs de U1, U2, U3, U4, U5 :
Exercice 29 :
a) U0 = 2 et Un+1 = 4Un - 2
U1 = 4U0 - 2 = 4 x 2 - 2 = 8 - 2 = 6
U2 = 22
U3 = 86
U4 = 342
U5 = 1366
b) U0 = 3 et Un+1 = -Un + 4
U1 = -U0 + 4 = -3 + 4 = 1
U2 = 3
U3 = 1
U4 = 3
U5 = 1
c) U0 = 0 et Un+1 = (Un)² + 3/(n + 1)
U1 = (U0)² + 3/(0+1) = 3
U2 = 9 + 3/2 = 21/2
U3 = 441/4 + 3/4 = 444/4 = 111
U4 = 12321 + 3/5 = ....
U5 = a toi de faire le dernier
Exercice 30 :
a) U0 = 2 et Un = 2U(n-1)
U1 = 2 x U0 = 2 x 2 = 4
U2 = 8
U3 = 16
U4 = 32
U5 = 64
b) U0 = -1 et Un = 4U(n-1) + 2n
U1 = 4 x U0 + 2 x 0 = (-4)
U2 = (-12)
U3 = (-42)
U4 = (-160)
U5 = A toi de faire...
c) U0 = 3 et Un = 2U(n-1) - 3
U1 = 2 x U0 - 3 = 3
U2 = 3
U3 = 3
U4 = 3
U5 = 3
