2014.1006= =0X  Y 2 2     2X + 3Y + 2 = 0 4 2 2 2CÂU VIB (...

2013.2014.1006

=

=

0

x  y 

2 2

     2x + 3y + 2 = 0

4 2 2 2

Câu VIb ( 2 điểm) 1)Phương trình đường thẳng AB:

x  y 

2 3 2

2 2

x y

0 00 0

1

 

13

9 5

, d(M,AB) =

+ AB = 2 13 _{, M(x}

₀

_,y

₀

_{)  (E)} 

1

2 AB.d(M,AB) = 2 x

⁰

 3 y

⁰

 2

+ S

MAB

=

2 2 2

x y x y

2 0 0 0 0

x y    

(2 3 ) .6 .3 5 (36 45) 81

          

3 5 9 5

   

+ BĐT Bunhiacôpxki

Suy ra  9 2  x

⁰

 3 y

⁰

  9  7 2  x

0

 3 y

0

  2 11  2 x

₀

 3 y

₀

 2 11 

x y x

2

  

0 0 0

  

18 15 5

  