Question

If csc theta=-5/4 and theta is between 180 and 270 what is the value of cos

Answer 1

to solve the question for cos θ will be found as follows:
csc θ=-5/4
but
csc θ=1/sin θ
thus
sin θ=-4/5
thus
θ=arcsin (-4/5)
θ=-53.130
but since the value lies between 180 and 270, our value will be:
180-(-53.130)=233.16
thus
cos233.16=-0.59958