How do you calculate #Cos^-1 [cos ((7pi)/6) ]#?
2 Answers
The answer will be
Explanation:
You can write
Thus we can clearly see the angle falls in the third quadrant. And the cosine value in third quadrant is always negative.
Hence,
coming back to the question
=
=
=
Explanation:
I treat
In general
The principal value is in the second quadrant, given here by the minus sign and