Answer:
4
Step-by-step explanation:
since the fraction is 1/4 you can multiply 4 by 4 and get sixteen and 4x1=4
4 of them are classical
12 of them are not
You take the 1/4 x 16 which equals to 4
4 becomes the number of classical music cd's
then you take 16-4 =12
12 becomes the number of cd's which are not classical
(d).
sin² β + cos² β = 1
cos (α + β) = cos α cos β - sin α sin β
cos α = √(1 - ) = 21 / 29
cos β = 12 / 13
sin β = √(1 - ) = 5 / 13
sin α = 20 / 29
cos (α + β) = × - × =
6/4