Period of sin wave = 1/2
Period of parent sine function is 2π.
This means the x value of sine function (sin(x)) has to be divided by 4π to get a period of 1/2 because 2π/4π = 1/2
Thus, our function will be of the form:

Maximum Value = 10
Minimum Value = -4
Amplitude of the function = (Maximum Value - Minimum Value)/2
So, amplitude of the function is 7
Thus, the function will be of the form:

The function has a y-intercept other than zero, this means the function will be of the form:

The y-intercept is 3. This means for x=0, y=3. Using the values, we get:
Thus the equation of the sinusoidal function becomes:
im going to say d but im not good at math
Answer:
The percentage increase in bird population in the second years is 4% .
Step-by-step explanation:
Given as :
During two years, the population of birds of an island became 7 times more than before.
The the percentage increase in first year = =
=40%
Let The percentage increase in second year =
= r%
So, According to question
The initial population of bird = x
The increase population of bird =7 times before = 7 x
Now,
The increase population of bird = initial population of bird × (1+
) × (1+
)
Or, 7 x = x × (1+
) × (1+
)
Or,
= 1.4 × (1+
)
Or, 7 = 1.4 × (1+
)
Or,
= (1+
)
Or, 5 = (1+
)
Or, (1+
) = 5
Or,
= 5 - 1
Or,
= 4
∴ r = 4 × 100
I.e r = 400
so, The percentage increase = r% = 4
Hence The percentage increase in bird population in the second years is 4% . Answer
Answer: 
Step-by-step explanation:
^{2} +(-3-3)^{2} \\\sqrt64+36\\\sqrt100\\=10](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%28-4-4%29%5E%7B2%7D%20%2B%28-3-3%29%5E%7B2%7D%20%5C%5C%5Csqrt64%2B36%5C%5C%5Csqrt100%5C%5C%3D10)