Quadratic Equation

 

Normally this is factored into

 Equation 1

 

The above is the usual solution.  In the limit that B>>A, the equation is approximately

 

This comes out of equation 1 in the limit of small A as the cancellation of two large terms.  The correct solution utilizes the positive sign in equation 1 so that

 

A more accurate approach is to multiply numerator and denominator of equation 1 by the appropriate factor so that

 

The desired solution now has the negative sign and no cancellation in the case B>>A.  This is implemented in CHAN.doc .htm for the case

Cis(1)=C-E, Cis(2)=B, Cis(3)=A