Use the halfangle identities to find the desired function va
Use the half-angle identities to find the desired function value. Assume that x >/= to 0.
If cos x = -1/4 and csc x < 0, find cot(x/2)
Solution
cos x = -1/4 and csc x < 0
=>x is in third quadrant
<=x<=3/2
=>/2<=x/2<=3/4
=>x/2 is in second quadrant
=>sin(x/2)>0, cos(x/2)<0
sin(x/2)=((1/2)[1-cosx]),cos(x/2)=-((1/2)[1+cosx])
=>sin(x/2)=(1/2)[1-(-1/4)],cos(x/2)=-((1/2)[1+(-1/4)])
=>sin(x/2)=(5/8),cos(x/2)=-(3/8)
cot(x/2)=cos(x/2)/sin(x/2)
cot(x/2)=-(3/8)/(5/8)
cot(x/2)=-(3/5)
