difficult array formula

[Shaz]

I have to formulas:

1) 1 = C/252*days(1)*d(1) + c/252*days(2)*d(2) + c/252*days(3)*d(3) +
d3

and

2) 1 = (1+C)^(days(1)/252)*d(1) + (1+C)^(days(2)1/252)*d(2) +
(1+C)^(days(3)/252)*d(3) + d(3)

days and d are ranges representing days and discount factors
respectively.

I would like to solve for C, the coupon that is paid in each period.

Formula 1 is easy:

=252*(1-B3)/sum(A1:A3*B1:B3)

where range B1:B3 is the d() array and A1:A3 is the days() array.

Now a formula for equation 2..........

 

[Gary L Brown]

If my algebra is correct...

C = ((1-d(3))^(252/(d(1)days(1))+(d(2)days(2))+(d(3)days(3))))-1

HTH,