You'll have to be easy on me, I am new to matlab and SO. I am having an issue using the matlab solver to calculate internal rate of return(IRR). I saw that the financial toolbox in matlab had a function for this, however I don't believe I have it installed and did not want to get the trial version on their site.

Given the simple nature of my particular IRR calculation, I figured it would be easy enough to simply code in matlab. It is the same yearly cashflow, so what I put into matlab was as follows:

Code: Select all

```
syms x k;
IRR = solve(investment == yrSavings* symsum((1+x)^-k,1, nYears));
```

It doesn't fail, and in fact gives a number. The only problem is the the result is incorrect! I type in the IRR manually and it never equals the investment. Using wolframalpha I found the actual solution, went back and manually typed in wolframalpha's answer, and the symsum function returned the correct result. I'm not sure what's up with the solver!