13=√(4^2+12^2+z^2);
13^2=16+144+z^2;
z^2=169-150=9;
z=+-3
[x²(x-3)-(x-3)]/[(x+1)(x+2)]>0
(x-3)(x²-1)/(x+1)(x+2)]>0
(x-3)(x-1)(x+1)/[(x+1)(x+2)]>0
(x-3)(x-1)/(x+2)>0,x≠-1
x=3 x=1 x=-2
_ + + _ +
--------(2) ---------(-1)-----------(1)----------(3)-----------
x∈(-2;-1) U (-1;1) U (3;∞)
4(1 - 5x) = 9 - 3(6x - 3)
4 - 20x = 9 - 18x + 9
-18x + 20x = 4 - 9 - 9
2x = -14
x = -7
Ответ: -7
Ответ: S≈1,167 кв. ед.
Объяснение:
y=√x y=2-x y=0 S=?
√x=0 x₁=0
2-x=0 x₂=2
√x=2-x
x+√x-2=0
Пусть √x=t>0 ⇒
t²+t-2=0 D=9 √D=3
t₁=√x=1 (√x)²=1² x₃=1
t₂=√x=-2 ∉ ⇒
S₁=₀∫¹(√x)dx=((2/3)*x³/²) ₀|¹=(2/3)*1³/²-0=2/3.
S₂=₁∫²(2-x)dx=(2x-(x²/2)) ₁|²=(2*2-(2²/2)-(2*1-(1²/2))=4-2-(2-(1/2)=2-1,5=0,5.
S=S₁+S₂=(2/3)+0,5≈0,667+0,5≈1,167.