Задача 47541 ...

vk325872489

2020-04-18 19:06:20

cos(-6π+8х)=sqrt(2)/2

sova

2020-04-18 20:22:00

cos(-6π+8х)=cos(8x-6π) по свойству четности косинуса

cos(8x-6π) =√2/2 ⇒

(8x-6π) = ± arccos(√2/2)+2πn, n ∈ Z

(8x-6π) = ±(π/4)+2πn, n ∈ Z

8х=6π ±(π/4)+2πn, n ∈ Z

[b]х=(1/8)*(6π ±(π/4)+2πn), n ∈ Z[/b]