Request TVM formula guidance

[Thomas Klemm]

(12-02-2014 05:33 AM)iMatt04bit Wrote:  // formula from the hp12c manual, solves to 0 for matched I converted to R, used below
f(x) = PV + (1+R*K) * PMT * ((1-(1+R)^-N)/R) + FV * (1+R)^-N

D[P+(1+R*K)*T*((1-(1+R)^(-N))/R)+F*(1+R)^(-N),R]

I just had to use single variable names P, T and F instead of PV, PMT and FV and use parentheses for the negative exponents.

HTH
Thomas