Celeb Glow
news | April 19, 2026

Is the range of arccos(x) arbitrary?

$\begingroup$

I understand that when you take the inverse of $f(x)=\cos(x)$, you have to limit the domain to ensure that the inverse is a function. This is limiting the range of the inverse.

I understand, then, why the ranges of $\arcsin(x)$ and $\arctan(x)$ are $[-π/2,π/2]$. However, I do not understand why the range of $\arccos(x)$ is $[0,π]$. Why can’t the range be $[-π,0]$? Is this something mathematicians have arbitrarily decided? Why have they done so?

$\endgroup$ 5 Reset to default

Know someone who can answer? Share a link to this question via email, Twitter, or Facebook.

Your Answer

Sign up or log in

Sign up using Google Sign up using Facebook Sign up using Email and Password

Post as a guest

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy