(b1b−1 −b2b)2 (a1 − a2)(b2 − b3) − (a2 − a3)(b1 − b2), , anadnd (( ))(( )) (( ))(( ))yˆL =yˆ L((ac=13 −c3c2−)c(2a1 −a1a2−)a(2b2 −a1a−2 )a2− −b2b−3 )b3− (−c2c−2 −c1c)1(a2a2−−aa33) ...