Perhaps a silly question – if you were finding the IRR in practice/doing a sensitivity analysis on interest rate change etc would you ever find people using the binomial expansion and finding the solution algebraically? Or would it just be a numerical solution that they leave to the computer – I imagine Excel etc has something that might be more precise than the 2 NPVs and approximate method (though appreciate that in practice there might be limited benefit to greater precision given all the other uncertainties in forecasting assumptions etc)
Welcome to the Opentuition forums. Excel can be used. Given potential importance of calculation, Excel might be used and then the solution checked using manual method to make sure no mistakes have been made.