How do you evaluate tan (Arc cos (sqrt2/2) )tan(Arccos(22))?

1 Answer
Jun 8, 2016

+-1±1. It is 1, if a = arc cos (sqrt 2/2)a=arccos(22) is restricted to be in the 1st quadrant...

Explanation:

Let a=arc cos (sqrt 2/2)=arc cos (1/sqrt 2)a=arccos(22)=arccos(12). As cos (+-a)= cos a, a is in the 1st quadrant or in the 4th. Accordingly, sin a = +-1/sqrt 2 and, therefore, tan a =+-1.

if a = arc cos (sqrt 2/2) is restricted to be in the 1st quadrant. the given expression tan a = 1...