Ответы и объяснения

2013-05-14T17:56:56+00:00

√10 cos x = - √5 | : √10

cos x = - √5 / √10

cos x = - √50 / 10

cos x = - 5√2 / 10

cos x = - √2 / 2

x = ±arccos (- √2 / 2) + 2πn, n ∈ Z

x = ±(π - π/4) + 2πn, n ∈ Z

x = ±3π/4 + 2πn, n ∈ Z