The input of each of these functions is always an angle, and as you learned in the previous sections, these angles can take on any real number value. Therefore the sine and cosine function have the same domain, the set of all real numbers, \begin{align*}R\end{align*}
Answer:
the answer is B
Step-by-step explanation:
i just took the test, hope this can help?
step 1
find the equation of the line
where
x-------> numbers of light bulbs
y-------> the total cost in $
let
A (0,0) B (10,18)
slope m=18/10-----> m=1.8
step 2
with m=1.8 and the point A (0,0)
y-y1=m*(x-x1)------> y=1.8x
step 3
for x=1
y=1.8*1------> y=$1.8
therefore
the answer is
the cost of a single light bulb is $1.8