Determine the domain of the function fx Squareroot x2 4x3
Determine the domain of the function f(x) = Squareroot x^2 - 4/x^3 - 4x. {x 2} {x|x notequalto 0, x notequalto plusminus 2} {x|-2
Solution
2)
The domain of a function is the set of numbers that can go in to a given function. In other words, it is the set of x-values that you can put in to any given equation.
When finding the domain, remember:
Here f(x)=
So by definition denominator cannot be zero.
So the value of x for which the denominator equals zero are, x=0,2,-2
Also the number under a square root must be positive, so x2- 4 should be always greater than zero.
x2 – 4 > 0
x2 – 4 + 4> +4
x2> 4
x > ±2
so -2 < x < 2
A)
{x< -2} U {x>2}
DOMAIN = (-,-3] U [3,)
B)
{x|x0,x ± 2}
DOMAIN = (-,-3] U [3,)
C)
{x|-2 < x < 2}
DOMAIN = (null set)
Since no elements can in the given region can give a proper definition to f(x).
D)
{x -2} U {x 2}
DOMAIN = (-,-3] U [3,)
