<span>sin^6(x)+cos^6(x)=(5/4)sin^2(2x)
</span>sin^6(x)+cos^6(x) = 5 sin^2(x)*cos^2(x)
(sin^2(x)+cos^2(x))(sin^4(x)+cos^4(x)-sin^2(x)cos^2(x)) = 5/4sin^2(2x)
1/8(3cos(4x)+5) = -5/8(cos(4x)-1)
<span>cos(4x) = 0
</span>x = πn-(7π)/8
x <span>= πn-(5π)/8
</span>x = πn-(3π)/8
<span>x = πn-π/8</span>
n ∈ Z
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Х(х²-36) / х+9 < 0
ОДЗ: х+9≠0, х≠ -9
х(х²-36) < 0
х(х-6)(х+6) = 0
х₁ = 0
х-6=0
х₂ = 6
х+6=0
х₃ = -6
+ - + - +
----₀--------₀-------₀--------₀--------> x
-9 -6 0 6
х∈(-9; -6)∪(0; 6)
Наибольшее целое х=5
80*2,5=200(руб.) заплатила Маша за клубнику
1000-200=800(руб.) сдача
Т к
x-y=3 то 3*-5-3=-15-3=-18