Calculate the circumference of a circle that has
(a) a radius of 7 cm.
(b) a radius of 56 cm.
(o) a diameter of 9.2 cm.
(d) a diameter of 98 mm.

The answers are a) 43.96 cm, b) 351.68 cm, c) 28.8 cm and d) 307.72 mm

The formula to calculate the circumference of a circle is C= π d, or C = π 2r, where d is the diameter and r is radius.

A - C=3.14 x 2 x 7 = 43.96 cm

B - C=3.14 x 2 x 56 = 351.68 cm

C - C=3.14 x 9.2 = 28.8 cm

D - C=3.14 x 98 = 307.72 mm

let f (x ) is a function and c be a positive real number,   the graph of the function g (x ) = f (cx ) is represented as follows.

when, c > 1,   the function compresses it in the x - direction.

when, 0 < c < 1, the function stretches it.

the function is g ( x ) = (9x )2.

the heighest power of x in g ( x ) = (9x )2 is 2, so the parent function is square function.

the equation of parent function is f ( x ) = x 2 .

the function is g ( x ) = (9x )2 and the parent function is f ( x ) = x 2 .

so, the functions f and g have the following relationship.

g ( x ) = f ( 9x ).

compare the function g ( x ) = f ( 9x ) with g (x ) = f (cx ).

c = 9 ( > 1 ).

so, the function g (x ) = (9x )2 compresses it in the x - direction.

step-by-step explanation:

the answer on e2020 was d.