The area of a circle (a) is given by the formula where r is the circle's radius. the formula to find r is . if and , r is centimeters.

For this case we have by definition, that the area of a circle is given by:

Where:

A: It is the area of the circle

r: It is the radius of the circle

We cleared the radius of the circle:

We choose the positive value:

b. 6

step-by-step explanation:

we are given the table representing an exponential function.

we can see from the table that, as x is increasing, the value of y is increasing in the power of 6.

i.e. the following relation is obtained,

x = 1, y = 6

x = 2, y = 36 =

x = 3, y = 216 =

x = 4, y = 1296 =

x = 5, y = 7776 =

so, the geometric series obtained is .

thus, the common ratio is given by = = 6.

hence, the common ratio is 6.