# Solving for single variable proving to be extremely difficult.

I have been at this equation for about two days now, and I can not for the life of me find a way to solve to i. If anyone can please show me a step by step into solving this, it would help me out so much. This equation was created by myself to show how compounding interest works if you add the original amount after each year. Please help me solve for i

$F = P(1+i)[\frac {(1+i)^n-1}{i}]$

solve for $i$

• What are $P$ and $F$ – Rubertos Apr 10 '15 at 16:51
• They are constants – Uys of Spades Apr 10 '15 at 16:51
• There is no closed form formula for $i$ when $n\ge 4$. One has to use a numerical method. – André Nicolas Apr 10 '15 at 16:52
• numerical method as in.. the long way? – Uys of Spades Apr 10 '15 at 16:53
• This computation is typically done using a financial calculator. All other variables are known, so you can usually enter their values and ask the calculator to find $i$. – MPW Apr 10 '15 at 16:54

## 1 Answer

Better read through this How to solve an nth degree polynomial equation We can't solve algebraically for a polynomial with degree greater than 4.And you dont need to either.If you know the values of the other variables just put them in and use a computer program http://www.wolframalpha.com/ to solve for it.