# Not able to solve following

• Dec 14th 2012, 01:14 PM
aayushmail007
Not able to solve following
I need to find a way to solve a

http://www.efunda.com/formulae/finance/images/apr_r.gif

I have n, P and C but I need to solve for a (its related to newton Raphson Method)

• Dec 14th 2012, 01:23 PM
chiro
Re: Not able to solve following
Hey aayushmail007.

Do you have to simply apply the Newton-Rhapson method to find the value of a (a good enough approximation)?
• Dec 14th 2012, 01:43 PM
aayushmail007
Re: Not able to solve following
i have no idea how to get to the solution to find value of a
• Dec 14th 2012, 01:57 PM
chiro
Re: Not able to solve following
Try expanding the (1+a)^n terms using the binomial method and then simplify these by noting that - 1 takes away the +1 term.
• Dec 14th 2012, 02:59 PM
aayushmail007
Re: Not able to solve following
still getting a big bad equation , need something simple to solve it
• Dec 14th 2012, 03:41 PM
chiro
Re: Not able to solve following
Try looking up solutions using Newton-Rhapson to solve implicit functions.

You can get the derivative by using implicit differentiation and you should get a function of a equal to zero where f(a) = 0 and this is done by some standard algebra.

Once you have this equal to zero then use a root finding algorithm to get your value for a.