Question 1140774
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At x=0, the function value is at its middle value and is increasing.  That means we can use a sine function with no horizontal shift.<br>
{{{y = a*sin(b(x-c))+d}}}<br>
a is the amplitude;
the period is 360/b  (assuming x is in degrees);
the horizontal shift is c (0 in this example);
d is the vertical shift  (axis, or center line)<br>
The center line is halfway between the minimum and maximum values; in this example the minimum and maximum values are 0 and 4.  That gives you the value of d.<br>
The amplitude a is half the difference between the minimum and maximum values.<br>
We already noted that because we are using a sine function the horizontal shift is 0.<br>
The period is 180 degrees; that gives you the value of b.<br>
You now have all the parameters required to write the function.