Question

Find the exact real value of arccosThe quantity one half

Answer 1

@zepdrix

Answer 2

The inverse cosine function will output an `angle`.
So that's what we're looking for, an angle.

The range of our inverse cosine is 0 to pi.
So it will only give us an angle lying in the first or second quadrant.

Answer 3

\[\large\rm \arccos\frac{1}{2}=\theta\]It's outputting an angle, that's why I'm letting it equal "theta", some unknown angle.

Answer 4

We can rewrite this in cosine,\[\large\rm \cos \theta=\frac{1}{2}\]Need more explanation on that step?

Answer 5

\[\cos ^{-1}\left(\frac{1}{2}\right)=\frac{\pi }{3}=60 {}^{\circ} \]