It is Choice C. Hope this helped!
I dont know for a fact but it could be 0.70710678118 but im not sure
Answer:
C
Step-by-step explanation:
Using sum/difference to product identity
• sin x - sin y = 2 cos(
) sin (
)
with x = 4Θ and y = 2Θ
Then
sin(4Θ) - sin(2Θ)
= 2 cos(
) sin(
)
= 2cos(3Θ)sinΘ → C