We are told that f(1) = -1.5, and that f(n+1) = -2f(n).
Then: f(2) = -2f(1) = -2(-1.5) = +3 (answer)
You want to end up with 
. Expand this using the angle sum identity for sine:
We want this to line up with 
. Right away, we know 
.
We also need to have
Recall that 
for all 
; this means
Then
So we end up with
Answer:
The answer is B.
Step-by-step explanation:
<em>A true proportion is a set of ratios that equal each other.</em>
<em> </em>For example, 1:2=2:4 is a proportion.
As we look through the list, we observe only B equals each other. Imagine 3:4 and 9:12 as a fraction. (¾ and 9/12). If we reduce 9/12, we get ¾. Thus, 3:4 = 9:12:)
I hope this helps!
