y = π x
The function rule that relates y (circumference) to x (diameter) is y = π x [pi × x]
Explanation:
Since x represents the diameter of the circle and y represents the circumference.
For a circle with radius r, circumference of the circle (y)equals,
y = 2πr ................................(1)
Diameter of a circle is twice the radius of the circle.
Assuming x as the diameter
[tex]x = 2\times r = 2r[/tex] ...........................(2)
Substituting (2) in (1), we get
y = π(2r) = πx ..............................................(3)
A function rule is an equation that determines the relation between a dependent variable and an independent variable. The relation between diameter of a circle and its circumference can be given as
Circumference = Pi × Diameter of circle
y = π × x
where π = 3.142
