Répondre :
1) R0 = 100cm
R1 = 0.9*100 = 90 cm
R2 = 0.9* 90 = 81cm
R3 = 0.9* 81 = 72.9 cm
2) Rn+1 = 0.9*Rn
3) Rn = R0 * 0.9^n
donc Rn = 100 * 0.9^n
donc R10 = 100*0.9^10 = 34.87 cm (environ)
R1 = 0.9*100 = 90 cm
R2 = 0.9* 90 = 81cm
R3 = 0.9* 81 = 72.9 cm
2) Rn+1 = 0.9*Rn
3) Rn = R0 * 0.9^n
donc Rn = 100 * 0.9^n
donc R10 = 100*0.9^10 = 34.87 cm (environ)