ANSWER

EXPLANATION
The frequency of a wave function refers to the number of times the graph repeats its cycle within the interval [0,2π]
We can observe explicitly from the graph that the frequency is half.
The period of the given function is 4π


Hence the frequency is half.
Answer:
The water temperature that produces the maximum number of salmon swimming upstream is approximately 12.305 degrees Celsius.
Step-by-step explanation:
Let
, for
.
represents the temperature of the water, measured in degrees Celsius, and
is the number of salmon swimming upstream to spawn, dimensionless.
We compute the first and second derivatives of the function:
(Eq. 1)
(Eq. 2)
Then we equalize (Eq. 1) to zero and solve for
:

And all roots are found by Quadratic Formula:
, 
Only the first root is inside the given interval of the function. Hence, the correct answer is:

Now we evaluate the second derivative at given result. That is:


According to the Second Derivative Test, a negative value means that critical value leads to a maximum. In consequence, the water temperature that produces the maximum number of salmon swimming upstream is approximately 12.305 degrees Celsius.
Answer:
The value of y would be 45.5
Step-by-step explanation:
To solve this problem, start with the base form of direct variation.
y = kx
Now we can use our original values to model the equation and find k.
35 = k(2.5)
14 = k
Now we can model the equation as:
y = 14x
Now to find y, when x = 3.25, simply put 3.25 into the equation.
y = 14(3.25)
y = 45.5
Points: (0,4) and (2,-3)
Find slope: (-3-4)/(2) = -7/2
4 = -7/2(0) + b, b = 4
Equation: y = -7/2x + 4
15 = 0.23x
x = 65.2
therefore 15 is 23% of 65.2