<span>5^(1/2log_5(4)) = </span><span>5^(log_5(4^(1/2)) </span><span>= 5^(log_5(2))= 2</span>
<span>8 - x</span>² <span>> 0
8-x</span>²=0
x²=8<span>
x</span>₁=-√8
x₂=√8
-∞ ___ - ___ (-√8) ___ + ___ (√8) ___ - ___ +∞
x∈(-√8;√8)
-5x² ≤ <span>x
</span>x+5x² ≥ 0
x+5x² = 0
<span>x(1+5x)=0
x</span>₁=0
x₂=-0.2
-∞ ___ + ___ [-0.2] ___ - ___ [0] ___ + ___ +∞<span>
x</span>∈(-∞;-0.2]∪[0;+∞)
(2-x)/x ≤ <span>0
</span>2-x=0
x₁=2
-∞ ___ - ___ (0) ___ + ___ [2] ___ - ___ +∞
x∈(-∞;0)∪[2;+∞)
1)sin4a/sina-cos4a/cosa=(sin4acosa-cosasin4a)/sinacosa=2sin(4a-a)/sin2a=
=2sin3a/sin2a
2)1/sin3a+1/sina=(sina+sin3a)/sinasin3a=(sina+sin3a)/sinasin3a=
=2sin2acosa/sinasin3a
3)2sin3a/sin2a *2sin2acosa/sinasin3a=4cosa/sina=4ctga
4ctga=4ctga