Log₁/₂(x²-5-6)≥-3
-3=log₁/₂(1/2)⁻³=log₁/₂8
log₁/₂(x²-5x-6)≥ log₁/₂8
a=1/2, 0<1/2<1 знак неравенства меняем<br>{x²-5x-6 ≤8 (1)
x²-5x-6>0 (2)
(1) x²-5x-6≤8, x²-5x-14≤0 (метод интервалов).
x²-5x-14=0. x₁=-2, x₂=7
+ - +
---------[-2]----------[7]------------->x
x∈[-2;7]
(2) x²-5x-6>0 (метод интервалов)
x²-5x-6=0. x₁=-1, x₂=6
+ - +
--------(-1)-----------(6)--------------->x
x∈(-∞;-10U(6;∞)
/ / / / / / / / / / / / / / / / / / / /
---------[-2]-----(-1)-----------(6)--------[7]------------->x
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
x∈[-2;-1)U(6;7]