Найдите 4sin(5п/[email protected])? если [email protected]=-0.6 и @=(п;3п/2)

Question

Найдите 4sin(5п/[email protected])? если [email protected]=-0.6 и @=(п;3п/2)

Answer 1

@=(п;3п/2)⇒3 чет

4sin(5п/[email protected])=4cosα

[email protected]=-0.6

cosα=√1-sin²α=√1-0.36=√0.64=±0.8⇒-0.8

4cosα=4*(-0.8)=-3.2