Urgent pour entrer en classe de terminale S a la rentree aidez svpppp

Bonjour,

2)
[tex]\\d_{1}=50\\d_{2}=0.99*d_{1}\\d_{3}=0.99^2*d_{1}\\d_{n}=0.99^{n-1}*d_{1}\\[/tex]
3)
a) la distance totale parcourue
b)
[tex]\\L_{n}=d_{1}+d_{2}+d_{3}+...+d_{n}\\=d_{1}+0.99*d_{1}+0.99^2*d_{1}+...+0.99^{n-1}*d_{1}\\=d_{1}*(1+.99+.99^2+...+.99^{n-1})\\=d_{1}*\dfrac{.99^{n}-1}{.99-1}\\=5000*(1-0.99^n)\\ [/tex]
c)lim =5000*(1-0)=5000

4)
b)L'algo donne la distance totale parcourue
c)2500=5000/(1-0.99^n)
=>1/2=1-0.99^n
=>0.99^n=1/2
=>n*ln(0.99)=ln(1/2)
=>n=68.9675...≈69 (jours)