Answer:
first one 5/8
Step-by-step explanation:
2 1/2 / 4 = 5/8
Answer:
16. =
17. <
18. <
Step-by-step explanation:
Cos (a-b) = cos(a)cos(b) + sin(a)sin(b)
cos (a+b) = cos(a)cos(b) - sin(a)sin(b)
so, cos(a-b) - cos(a+b) =
=cos(a)cos(b) + sin(a)sin(b) - [cos(a)cos(b) - sin(a)sin(b)]
=2sin(a)sin(b)