ответ: 1.19 . x = 2π + 3πn , nЄ Z ; 1.21 . x = ( - π/3 ± π/6 ) + 2πn , nЄ Z .
Объяснение:
1.19 . ctgx/3 = - 1/√ 3 ;
x/3 = arcctg( - 1/√ 3) + πn , nЄ Z ;
x/3 = π - arcctg( 1/√ 3) + πn ;
x/3 = π - π/3 + πn ;
x/3 = 2π/3 + πn ; │X 3
x = 2π + 3πn , nЄ Z ;
1.21 . cos( x + π/3 ) = √ 3/2 ;
x + π/3 = ± arccos( √ 3/2) + 2πn , nЄ Z ;
x + π/3 = ± π/6 + 2πn ;
x = ( - π/3 ± π/6 ) + 2πn , nЄ Z .
