Объяснение:

arctg(tg

13

10π

)=?

2

π

<

13

10π

< π⇒

13

10π

=π−

13

3π

tg

13

10π

=tg(π−

13

3π

)=tg(−

13

3π

),

2

π

< −

13

3π

<

2

π

arctg(tgα)=α,esli−

2

π

< α <

2

π

.

arctg(tg

13

10π

)=arctg(tg(−

13

3π

))=−

13

3π