Question #9ed58
1 Answer
Dec 21, 2016
Explanation:
Assuming 'x' is referring to multiplication, we will use the following:
Definitions of
#sec(theta) = 1/cos(theta)# #tan(theta) = sin(theta)/cos(theta)#
#sin(-theta) = -sin(theta)# #cos(-theta) = cos(theta)#
Well known angles:
#sin(pi/6) = 1/2# #cos(pi/6) = sqrt(3)/2# #cos((5pi)/6) = -sqrt(3)/2#
With those, we have
#=1/cos((5pi)/6)((-sin(pi/6))/cos(pi/6))#
#=1/(-sqrt(3)/2)((-1/2)/(sqrt(3)/2))#
#=2/3#