HP 48GX Analytical and Numerical Methods

[MNH]

Does anyone have the book Analytical and Numerical Methods with the HP 48 G/G+/GX Programmable Calculator by Martha A. Crawford that they'd like to sell to me? The book is out of stock on several websites. I'm interested in the Newton-Raphson method and how to use it to solve for the missing parts of a circular curve.

One example would be, find the radius of a circular curve given only the chord length and the arc length.

chord = 2Rsin(Δ/2)
arc = πΔR/180

Notes: The Δ symbol is the central angle. The π symbol is pi.

Another example would be, find the radius of a circular curve given only the tangent length and the arc length.

tangent = R tan(Δ/2)
arc = πΔR/180

A typical circular curve solution might be

Δ = 48°00'00" @ Central angle
R = 500.00' @ Radius
L = 418.88' @ Arc length
T = 222.61' @ Tangent length
CH = 406.74' @ Chord length

I'm new to iterative methods. How do you know what a good best guess would be for a particular situation?