Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

How do you find the domain of f(x)=arcscos(e^x) ?? The answer is (-infinity, 0] but I don't understand why!?

Update:

arccos(e^x) **

1 Answer

Relevance
  • Pope
    Lv 7
    4 years ago

    The domain of the arccos function is [-1, 1].

    In the function arccos(e^x), the argument of the arccos function is e^x. It must be on the domain above.

    -1 ≤ e^x ≤ 1

    But e^x is positive for all real x, so reject the non-positive part of the interval.

    0 < e^x ≤ 1

    lim e^x < e^x ≤ e^0

    x→-∞

    -∞ < x ≤ 0

Still have questions? Get your answers by asking now.