!" x x x + + ≥ − + !"#$%& ∈¡ '(&)*(+,)& -(.,)&..,/ !" 01234,0567&89: ; 34( <) = = > > >= ?7 @A , ,B , A:A #5A@A2C A C D#E74! FC # !" ?6&* , #E x π π < < C D4;G4H&C ?I6&+&*6& $%& !" ?6J4KDL , > x y + = M7NEO4$:7NEOP:2 :2 Q:%7RJ4C &%'& !" 6ST%7&96U(V)#EWT ∆ K &-9.*C XYWTNZ U#E66#$ ∆ C XYWG5UY&"#$WT ∆ C [2 ∆ U(V)716\ , C ( )* !" + x x x + + ≥ − + ]1& ≠ K , x x x x = − + + = ⇔ = − * +&.* ⇔ &* ^_&PN `^_! ( V ,a b V)S = −∞ − ∪ − C C C '(&)*(+,)& -(.,)&..,/(,) *,(,)4E_+&./ ⇔ &c, (10!"#$%&) ≠ ,(,)!"#$%& , , , , a m m m m m m m ∆ < ⇔ < < − + + < < − ⇔ ⇔ ⇔ < − − < > `^1/+,!"#$%&C C C C C +, d *> d J *> x *=>e:= ,==:B x S = x x S S = *e: C C C , C #+, &* , #E x π π < < C K = 6 , 6 > x x x= − = ⇒ = ± X x π π < < 2&*+ , x = − 6&*+ C C C C # ?I6&+&*6& K 6 6 6 C6 6 6 , x x x x VT x x x x x x x − = − = = = C C $ , > x y + = ,e f =c a b c c= − = ⇒ = ⇒ = ,a a a= ⇒ = ⇒ = > eb b b= ⇒ = ⇒ = g , *(+fV):g *(fV) U , *(+V):U *(V):[ , *(V+):[ *(V) C C C C C & +, , -, U(V)#E ∆ &-9.*C K d ∆ 2 (V ,) d n n ∆ = − = r r hN(&+)-(9+)*9&-9+,* i*N(UV ∆ )* f hWG5U1Di ,e ( ) ( ) x y− + − = K[(&V&.) ∈∆ , ( ) ( ) AB x x= − + + − = e , x x⇔ − + = h#0! X_910K[2 ∆ 66[U(V)716 \ , C C C C C C C C . !" 01234,0 5 67&89: ; 34( <) = = > > >= ?7 @A , ,B , A:A # 5 A@A2C A. !" 6ST%7&96U(V)#EWT ∆ K &-9.*C XYWTNZ U#E66#$ ∆ C XYWG 5 UY&"#$WT ∆ C [2 ∆ U(V)716 , C . r hN(&+)-(9+)*9&-9+,* i*N(UV ∆ )* f hWG 5 U1Di ,e ( ) ( ) x y− + − = K[(&V&.) ∈∆