NGHÖ AN DIÓN CHAU !"#$ %"pht ( không k thi gian giao đ) &' ()$" x x − ≥ − − x x+ − − ≤ ()" !"#$%$&'%%()!*+,-!! .'% / 0 1 2 3 )45 2 1 )%5567%58#9: ()*" );<= α > / π + α = 6? π α < < @A"'B !C C x A − = − ()+" ! ABC∆ DD<=0 < =%<E=2%);F .8G$HE I9;J ABC ∆ .8G$KL+ b m G *!M'%<+E ()," !KN d COL>=6$'%PQO );&!M'%P+KN d R+KN,P6$6(D6?KN d R++L+6?KS ( ) ( ) 3x y− + − = +T+L+D !!6?KN d ()-" B%T!%<E D ! ! ! / A B C c A c B c C+ + − = (Cn b coi thi không gii thch g thêm) ./0123"44444444444444444444444444444444444444444444444444456789:3;44444444444444444444444444444444444444444444 %<$='>?&>@ () AB9)3C BDE x x − ≥ − − x x x − + ⇔ ≥ − − Q.UVC= x x x − + − − ECWGVC C −∞ +∞ OC> >X>X>O CO OXO>X> CO O>X>X> VC >XXOXX>O RYL9%J#$ O Q Q Z S = ∞ ∪ × x x+ − − ≤ .UVC= x x+ − − QVC= x x = ⇔ = − ECWGVC C −∞ − +∞ VC >O> RYL9%J#$ [Q ZS = − × \5 / 2 0 1 21 3 x + + + + + + + + + = =020 \567R54]JG^L#$5_`567#$8J5B a67;bG^L67; 6$ > 1 1 1 e M + ⇒ = = P5.'%2D45#?#$1 2M⇒ = c 020 020 020 020 / 020 2 020 0 020 1 020 12 020 3 020 x S − + − + − + − + − + − + − + − + − + − = x S ≈ / .8#9: x x S S= ≈ × )D ! c α α = − = / / − = ! c α ⇒ = ± 6 π α < < ` ! α > RYL ! c α = ⇒ ! c α α α = = / A π α α α + = + = − L α = - A + = − = + − × !C C x A − = − = ! !C C x c x x+ − − = ! !C C c x x− − = ! !C>C !C C c x x c− − = !C>Cc / !0a b c bc c= + − = 2 2 + − =/3 /3 1BC a⇒ = = = % / ABC S b c A ∆ = = 2 = % × / / b a c b m + − = = 1 2 / + − = 13 b m⇒ = ≈ % × /G *!M<+E T a h 1 ABC a S h a ∆ = = ≈ /3% ( ) d M d − − + = + − = × " ∆ #$KN,P6$6(D6?G )D d COL>= Q d n⇒ = − uur R d∆ ⊥ ` ∆ DR) c u ∆ uur = Q d n = − uur c%5J ∆ x t y t = + = − − )D ( ) ( ) 3x y− + − = ⇒ d%eQQ&;@= " l #$+L+JKS6 ffl d ` l DGHCOL>%= l +CA6? e d l R⇒ = ⇔ m− + = + − m⇔ + = m m = − ⇔ = − − RYLD+L+g%^L`4h$ l x y l x y − + − = − − − = 0 )!%<E D A B C π + + = A B C π + ⇒ = − ⇒ ! A B C+ = ÷ R)= ! ! ! c A c B c C + + − = ! ! A B A B c + − ÷ ÷ C − = ! ! C A B A B c − + − ÷ ÷ = C A B − − ÷ = / A B C =Rc% × ijklIml inP fl+"D&%$6oA6$p-6?8G% &!6o!J'%M4,L7 f.'%J$&'%#$q'%J!$$6$#$%S+R;Gr0#$%S$0Q 01#$%S$1 . NGHÖ AN DIÓN CHAU !"#$ %"pht ( không k thi gian giao đ) &' ()$"