微积分求解:calculus test

问题描述:

微积分求解:calculus test
How many years will it take $500 to grow to $6500 if the investment earns interest at the rate of 30% compounded(1)annually(2)continuously?(answer one decimal) lg13约1,113 ln13约2.56

10 years,
for 500*(1+30%)^n=6500
1.3^n=13
lg1.3^n=lg13
nlg(13/10)=lg13
n(lg13-lg10)=1.113
0.113n=1.113
n≈10