Question

Решите уравнение log1/2(x2-4x-1)=-2

Answer 1

log1/2(x2-4x-1)=-2log1/2(1/2)
x2-4x-1=(1/2)^-2
x2-4x-1=4
x2-4x-5=0
D=16-4•(-5)=36=6^2
x1=(4-6)/2=-1
x2=(4+6)/2=5