In: Math
Which expression is equivalent to secαcos(2α) for all values of α for which secαcos(2α) is defined?
Select the correct answer below:
21−tan2α
2cos2α
2sin2α
2cosα−secα
1−tan2α
sec cos ( 2 )
cos ( 2 ) = 2 cos^2 - 1
sec = 1 / cos
so we get
1 / cos ( 2 cos^2 - 1)
1/ cos * 2 cos^2 - 1/ cos
2 cos - 1/ cos
2 cos - sec
2 cos - sec |