solve false answer with a exponential equation

hello i am trying to solve an equation and each time that i try to solve it with the matlab it keeps giving me a false value it doenst give any error or anything... here is the code

syms x
Cf=1;
C_0=10;
M=1.1*1350;
m=155;
thao=M/m;
C=C_0*exp(-x/thao)-Cf;
solve(C,x)

and it keeps giving me the

ans=(297*log(10))/31 %log(10)=1 so, 297/37 that it is aprox 9.56 when the real value is 22.06 aprox

obviusly false. i couldnt find any error or problem in the code. anyone had the same problem?

Answer 1

[Walter Roberson]

log(10) is not 1. log() is natural log. The calculation gives the value you expect. Use vpa() or double() to see the decimal equivalent.

[franco otaola]

thanks, it is really bizarre that it use log() for ln()... i wouldnt expect that...

[Walter Roberson]

I looked around a few months ago, and I could not find any programming language which used ln() for natural log. All of the major languages I checked used log()