arccos(1/2)?

I'm pretty sure the answer is supposed to be pi/3, but I just wanted to confirm this. What is arccos(1/2) equal to in radians?

Update:

What's really sad is that for my College Pre-Cal final exam I got this question with these answer choices:

A) -pi/6

B) pi/6

C) pi

D) No solution in the domain

E) 1

F) None of the above

When I chose F, None of the above, it was marked as incorrect. I guess I'm going to have to dispute this with the professor. Thanks guys.

Comments

  • cos θ = 1/2

    θ = π / 3 , 5 π / 3 (quadrants 1 and 4)

  • This Site Might Help You.

    RE:

    arccos(1/2)?

    I'm pretty sure the answer is supposed to be pi/3, but I just wanted to confirm this. What is arccos(1/2) equal to in radians?

  • pi/3.

  • The correct answer is pi/3.

    If you have copied the problem statement correctly, then F is the correct answer, and I suggest that you talk to your professor about it.

  • it is

    π/3 ( 1st quadrent) or 5π/3 ( 4th quadrent)

    [remember that cos is +ve in 1st & 4th quadrent, & -ve in 2nd & 3rd

    sin is +ve in 1st & 2nd & -ve in 3rd & 4th ]

  • it can be pi/3 or -pi/3 as you said

Sign In or Register to comment.