Chapter 2, Problem 25P

When converting resistances connected in a formation to a ∆ formation as shown in Fig. P2.21. the resistance R ₁ is given by equation (2.69).

(a) Suppose $R_1=6,R_a=R,R=3R$, and $R_c=100+R$, all measured in ohms. Substitute these values into equation (2.68) to obtain the following quadratic equation for R.

$R^2-10R-200=0$ (b) Solve the quadratic equation for R by the methods of completing the square and the quadratic formula.