What is the ratio DE of the length of to the length of BC?

1:4

Step-by-step explanation:

so we are comparing the arc lengths to get the ratio of DE:BC

to get arc length BC as

and for DE as

so divide DE by BC where beta pi r will cancel out. and you remain with 1/4 Wich will translate to 1:4

since no one answered yet i will give it a shot, not completely sure tho.

i think it should be y=cos(x+2pi), (third answer, answer c)

good luck.