Domain Question: domain of f(x) = 9 / sqrt[t]

[Jason76]

Domain of

\(\displaystyle f(x) = \dfrac{9}{\sqrt{t}}\) ?

Is it \(\displaystyle [0,\infty)\) The book says not.

 

[srmichael]

No, because t cannot be 0. It is (0, +∞).

 

[JeffM]

Domain of

\(\displaystyle f(x) = \dfrac{9}{\sqrt{t}}\) ?

Is it \(\displaystyle [0,\infty)\) The book says not.

It depends what t is, but whatever t is, your answer is wrong.

If t = 0, f(x) is defined for no real value of x. Otherwise, f(x) is defined for all real x (although if t < 0, f(x) itself is not real).

 

[lookagain]

Domain of

\(\displaystyle f(x) = \dfrac{9}{\sqrt{t}}\) ?

Jason76, check the function in the question again.

Is it supposed to be \(\displaystyle \ "f(x) \ = \ \dfrac{9}{\sqrt{x}}", \ \) or is it supposed to be \(\displaystyle \ "f(t) \ = \ \dfrac{9}{\sqrt{t}}?"\)