Решите выражение
sin 13pi/12 *cos 13pi/12

3∗sin(

12

13pi

)∗cos(

12

13pi

)=

2

3

∗2∗sin(

12

13pi

)∗cos(

12

13pi

)=

=\frac{3}{2}*sin( \frac{2*13pi}{12}) = \frac{3}{2}*sin( \frac{13pi}{6}) = \frac{3}{2}*sin(2pi+ \frac{pi}{6}) = \frac{3}{2}*sin( \frac{pi}{6}) = \frac{3}{2}*\frac{1}{2}==

2

3

∗sin(

12

2∗13pi

)=

2

3

∗sin(

6

13pi

)=

2

3

∗sin(2pi+

6

pi

)=

2

3

∗sin(

6

pi

)=

2

3

∗

2

1

=

=\frac{3}{2}*\frac{1}{2} = \frac{3}{4}=

2

3

∗

2

1

=

4

3