3 3 3 2COS SIN−     2 12 123IΠ Π Π Π    − + − +2 2K K  ...

Câu 1

:

3 3

3 2

cos

sin

2

12

12

3

i

π

π

π

π

+

+

2

2

k

k

3 2

cos

12

sin

12

,

0,1,..., 9

=

+

=

10

10

z

i

k

2

10

10

7

3

6



 

3

1

1

7

3

6

33

2

10



 

= −

= −

( )