Answer:
$9450
Step-by-step explanation:
We will use compound interest formula:

Where
F is future amount [what we want to figure out]
P is present amount [9000]
r is rate of interest [since we want for 6 months, the annual interest divided by 2 is r. So r = 10/2 = 5% or 0.05]
t is the time [ the time period is for 6 months so t = 1 since we already converted the interest rate to 6 month chunk]
Putting in formula, we get:

Yes the cost is a function because with each hour it costs $5 more than before, keeping a pattern
Hope this helps ya :D
Answer:
11/12
Step-by-step explanation:
tan θ = sin θ / cos θ
cos θ = sin θ / tan θ
cos θ = (√23/12) / (√23/11)
cos θ = (√23/12) × (11/√23)
cos θ = 11/12