task/29453518
Вычислить arcsin( sin(- 17π/5) )
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arcsin( sin(- 17π/5) ) =|| постепенно: куда спешим || = arcsin( -sin(17π/5) ) =
arcsin( -sin( 2π + ( π +2π/5) ) ) = arcsin( -sin( π +2π/5) ) = arcsin( sin(2π/5) ) =
= 2π/5 .
* * * - π/2≤ 2π/5 ≤ π/2 ; sin(-φ) =- sinφ ; sin(2π+φ) =sinφ ; sin(π+φ) =- sinφ* * *