Guest

f(x)=root(log 0.3 (x-1)/x 2 -2x-8)

f(x)=root(log0.3(x-1)/x2-2x-8)

Grade:

1 Answers

Ramesh V
70 Points
13 years ago

The domain of f(x) is :

necessary condition : (x-1)>0

the value under f(x) shld always be positive

case 1:

log0.3(x-1) > 0  and (x+2)(x-4) > 0

x-1 > 1  and (x+2)(x-4) > 0  and x>1

the overlapping region is x > 4

case 1:

log0.3(x-1) < 0  and (x+2)(x-4) < 0

x-1 < 1  and (x+2)(x-4) < 0

x<2 and -2<x<4  and x>1

the overlapping region is : (1 , 2)

the domain is : (1,2) U (4,infinity)

--

Regards

Ramesh

Think You Can Provide A Better Answer ?