Answer:
f(x) = 5*sin( (5/4)*x) + 2
Step-by-step explanation:
A general sine function can be written as:
f(x) = A*sin(w*x) + M
Where:
A is the amplitude
w is the frequency of the function
M is the midline
Here we know that we want to have:
An amplitude of 5. Then, A = 5
A midline of 2, then M = 2
And a period of (8/5)*pi
For now, we can write our function as:
f(x) = 5*sin(w*x) + 2
Now, we know that for a function of period T, is always true that:
f(x) = f(x + T)
here, the period is T = (8/5)*pi
knowing that sin(0) = sin(2*pi)
Then we must have:
sin(0) = sin(w*0) = sin(w*( 0 + (8/5)*pi)) = sin(2*pi)
Then the arguments of the third and fourt parts must be the same, thus:
w*(8/5)*pi = 2*pi
We can solve this for w now:
w*(8/5) = 2
w = 2*(5/8) = (5/4)
Then the function is:
f(x) = 5*sin( (5/4)*x) + 2
