Răspuns:
1.log1/4(x)
f(x)=0 => x=1
Baza e subunitara=> f(x)>0 pt x∈(01] si
f(x)<0 pt x>0
f(x)=1 =. > x=1/4
Graficul e in atasament
2.f(x)=-log5(x)=log5(x)⁻⁻¹=log5(1/x)
f(x)=0=>1/x=1=> x=1
baza 5>1=> f(x)<0 pt 1/x<1 adica x>1
f(x)>0 pt 1/x>1 => x<1
f(x)=1 =>1/x=5 x=1/5
3.f(x)=1/2log₂(x)=log₂x^1/2=
log₂√x
f(1)=log₂√x=1=>√x=4 f(4)=1
Deoarece 2>1 f(x)>0 pt √x>1 adica pt x∈(1,+∞)
Pt x(0,1) f(x)<0
Explicație pas cu pas: