A Simple one:

The domain of function f(x)=$\sec^{-1} x$ is:
a)(-1,1)
b)R-[-1,1]
c)R-(-1,1)
d)[-1,1]

Question

A Simple one:

The domain of function f(x)=$\sec^{-1} x$ is:
a)(-1,1)
b)R-[-1,1]
c)R-(-1,1)
d)[-1,1]

foolaroundmath · Answer

The question  is equivalent to asking, what values can $\sec{x}$ take?
Can you reason this why it is so?

ujjwal · Answer

I guess its asking what values can x take? Isn't it?

foolaroundmath · Answer

I should have changed the $x$ in my first post to avoid confusion.
$\sec^{-1}x$ is the inverse function of $\sec{x}$. The domain of $f(x) $ is the range of $f^{-1}x$ and vice-versa.

The question asks what value can $x$ take so that $\sec^{-1}x$ is defined.
That is equivalent to asking $y = sec^{-1}x$ or $x = \sec{y}$ 
i.e. what values can $\sec{y}$ attain

ujjwal · Answer

I think it should be [-1,1]..

But it says the answer is R-(-1,1)

ujjwal · Answer

@FoolAroundMath

foolaroundmath · Answer

What values can $\sec{x}$ attain ? $\sec{x} = 1/\cos{x}$

ujjwal · Answer

Thanks!