49 À :: `+`(`*`(2, `*`(`^`(sin, 2), `*`(x))), `*`(`+`(2, `-`(sqrt(2))), `*`(cos, `*`(x))), sqrt(2), `-`(2)) = 0            Á :: [5π/2;7π/2] 

ÐÅØÅÍÈÅ 

 

 

ÎÒÂÅÒ 

À :: `+`(`*`(2, `*`(Pi, `*`(k)))); 1; `+`(`*`(`+`(`*`(3, `*`(Pi))), `/`(1, 4)), `*`(2, `*`(Pi, `*`(k)))); 1; `+`(`*`(`+`(`*`(5, `*`(Pi))), `/`(1, 4)), `*`(2, `*`(Pi, `*`(k)))), `in`(k, Z) Á :: `*`(`+`(`*`(11, `*`(Pi))), `/`(1, 4)); 1; `*`(`+`(`*`(13, `*`(Pi))), `/`(1, 4))