Question

Which equation relates the circumference of a circle in centimeters, y, to the diameter of the circle in centimeters

Answer 1

we know the general equation of line is,

`y=mx+b`

Where m is the slope of the line and b is the y intercept.

From the given graph we get that it is straight line which passes through the origin.

When x=0, we get y=0

Hence the y intercept is 0

Slope is given by,

`=\frac{change\text{ in y}}{change\text{ in x}}`

(1,3) and (2,6) are the two pointa on the line, (approx)

we get,

`=(6-3)/(1-2)=3`

we get,

`y=3x`

we get y is directly proportional to x, that is Let pi (approximtely equals to 3) be the constant of proportionality we get,

`y=\pi x`

we get,

`\pi=(y)/(x)`

Answer is:

option D,

`\pi=(y)/(x)`