Question

3. Which of the following is not in the domain of

f(x) = In(4-3x)/5x+2

A)-5/2
B) -2
C)2/5
D)3/4
E) 3

Answer 1

E

Explanation:

First, things first, The denominator can't equal 0 since this is a fraction

`5x + 2 = 0`

`x = - (2)/(5)`

Also, the argument of the natural log in the numerator must be greater than 0

`(4 - 3x > 0`

`- 3x > - 4`

`x < (4)/(3)`

So x must be less than 4/3, and not equal to -2/5 so the domain of this function is

(-oo,-2/5) U (-2/5,4/3)

The number that does not lie I. this interval is E.