# PV formula solving for i

• May 8th 2012, 02:33 AM
downthesun01
PV formula solving for i
How can I solve somthing like this for i

$2=\frac{1-(\frac{1}{1+i})^{40}}{i}$

The textbook I'm looking simply states that it's "difficult" to solve by and that it's best to just use a financial calculator.
• May 8th 2012, 07:58 AM
ILikeSerena
Re: PV formula solving for i
Quote:

Originally Posted by downthesun01
How can I solve somthing like this for i

$2=\frac{1-(\frac{1}{1+i})^{40}}{i}$

The textbook I'm looking simply states that it's "difficult" to solve by and that it's best to just use a financial calculator.

Hi downthesun01! :)

The solution is $i \approx 0.499999954781082$

See here:
2=\frac{1-(\frac{1}{1+x})^{40}}{x} - Wolfram|Alpha

Indeed, solving it analytically is not going to work out.