A) sin(x - π/6) > 0
arcsin0 + 2πn < x - π/6 < π - arcsin0 + 2πn, n∈Z
2πn < x - π/6 < π + 2πn, n∈Z
π/6 + 2πn < x < π + π/6 + 2πn, n∈Z
π/6 + 2πn < x < 7π/6 + 2πn, n∈Z
<span>б) tgx(x - </span>π/4) ≤ 0
- π/2 + πn ≤ x - π/4 ≤ arctg0 + πn, n∈Z
- π/2 + π/4 + πn ≤ x ≤ π/4 + πn, n∈Z
- π/4 + πn ≤ x ≤ π/4 + πn, n∈Z
task/29460089
Пусть f(x ) +f(y) = f(z ) , f(x) = Log (1+x) / (1 - x)
z → ?
Log (1+x) / (1 - x) + Log (1+y) / (1 - y) = Log (1+z) / (1 - z) ;
* * * x ; y ; z ∈ (-1 ; 1) * * *
Log (1+x)(1+y) /(1 -x)(1 -y) = Log (1+z) / (1 - z) ;
(1+x)(1+y) / (1 -x)(1 -y) = (1+z) / (1 - z );
(1+x)(1+y) (1 -z) ) = (1 - x )(1 -y)( 1+z) ;
( (1 - x )(1 -y) + (1+x)(1+y) )* z =(1+x)(1+y) - (1- x)(1- y ) ;
2(1+xy) *z = 2(x+y) ;
z = (x+y) / (xy +1) . xy ≠ - 1
Решение смотри в приложении ответ 6