(u-5)(5u+1)(3u-5)=(5u^2 +u- 25u-5)(3u-5)= 15u^3-15u^2+3u^2-5u-75u^2+125u -15u + 25=15u^3- 87n^2+105u + 25
-π/4+2πk≤x/4 -1≤5π/4+2πk
-π/4 +1+2πk≤x/4≤5π/4 +1+2πk
-π+4+8πk≤x≤5π +4+8πk,k∈z
(log(2)2x^-1/log(2)x * log(2)2x²/log(2)x) : (log(2)x/log(2)2x * log(2)x/log(2)2x^-2)<40
((1-log(2)x)(1+2log(2)x)(1+log(2)x)(1-2log(2)x)-40log(2)^4 x)/log(2)^4 x<0
((1-log²(2)x)(1-4log²(2)x)-40log(2)^4 x)/log(2)^4 x<0
(1-4log²(2)x-log²(2)x+4log(2)^4 x-40log(2)^4 x)/log(2)^4 x<0
(1-5log²(2)x-36log(2)^4 x)/log(2)^4 x<0
1-5log²(2)x-36log(2)^4 x<0, log(2)^4 x>0 при любом х>0
36log(2)^4 x +5log²(2)x-1>0
log²(2)x=a
36a²+5a-1>0
D=25+144=169 √D=13
a1=(-5-13)/72=-1/4
a2=(-5+13)/72=1/9
+ _ +
_________________________________
-1/4 1/9
a<-1/4⇒og²(2)x<-1/4-нет решения
a>1/9⇒log²(2)x>1/9⇒(log(2)x-1/3)(log(2)x+1/3)>0
+ _ +
____________________________________
-1/3 1/3
log(2)x<-1/3⇒x<1/∛2 и log(2)x>1/3⇒x>∛2
(х-8)(х+6)<0
раскрываем скобки, x (в квадрате)-2х-48<0
D=196
x1= -8
x2= 6
Непотрыбно змынювати знак тема на це звички