Answer:
B
Step-by-step explanation:
using the identity
sin²x + cos²x = 1 ( subtract 1 from both sides )
sin²x + cos²x - 1 = 0 ( subtract sin²x from both sides )
cos²x - 1 = - sin²x
then
[tex]\frac{cos^20-1}{4sin^20}[/tex]
= [tex]\frac{-sin^20}{4sin^20}[/tex] ← cancel sin²Θ on numerator and denominator
= [tex]\frac{-1}{4}[/tex]
= - [tex]\frac{1}{4}[/tex]
