Question

Select the correct answer. Which function's domain consists of only real numbers greater than 3? ОА. f(x) = 3х O B. (a)= VI OC. f(x) = 3x + 4 OD. (t)= ve

Answer 1

We have the following functions:

`\begin{gathered} f(x)=3x \\ f(x)=\sqrt[]{x} \\ f(x)=3x+4 \\ f(x)=\frac{1}{\sqrt[]{x-3}} \end{gathered}`

notice that on the first and the third case, the functions are linear, thus, their domain is the set of real numbers.

The second function is a square root function, which has the set of positive real numbers as its domain.

Finally, we can see that on the last function, the denominator becomes 0 when x = 3. And also, if x is less than 3, we get a negative number inside the square root, which cant happen in this case. Therefore, its domain is the set of real numbers greater than 3.