Question

ln(1000)=ln(1100-c)*0.5+ln(1000-c)*0.5求c怎么求

Answer 1

ln(1100-c)*0.5+ln(1000-c)*0.5=ln(1100-c)*(1000-c)*0.5^2

所以(1100-c)*(1000-c)*0.5^2=1000 (1100-c)*(1000-c)=4000

解出c=1050+10根号65 或者1050-10根号65