Answer:
First one
Step-by-step explanation:
x-5y/6
Answer:

Step-by-step explanation:
Using the general equation
, we already know that
and
, but we need to find
from the period:

Hence, the cosine function is 
<span><span>The average rate of change formula is basically the slope formula, where you plug in: f(b)-f(a)/b-a. Then plug in the numbers. [f(0)=1,f(3)=7)]. So, 7-1/3-0. 6/3 is 2 so the average rate of change is 2. And that makes sense because the average rate of change is always the slope, and the slope is 2.</span></span>