Question

The area of a circle is given by: A(r) = πr squared, where A is the area and r is the radius of a circle.

Express the radius r as a function of the Area.

Answer 1

r(A) = 2Aπ ?

Answer 2

i think you need to divide and take square root

Answer 3

\[\large A = \pi r^2\]

Answer 4

to express radius as a function of something, we need to isolate \(r\)

Answer 5

start by dividing \(\pi\) both sides

Answer 6

A= 4

Answer 7

hmm

Answer 8

this is just algebra gimmick, you don't need to *actually* divide stuff.. just put the \(\pi\) under A, thats all...

Answer 9

\[\large A = \pi r^2\]

divide \(\pi \) both sides, you get :

\[\large \dfrac{A}{\pi} = r^2\]

Answer 10

take sqrt both sides, you get :


\[\large \pm \sqrt{\dfrac{A}{\pi}} = r\]

Answer 11

since radius is defined as the `distance` between center and point on circle, it can never be negative. so discard the negative value

Answer 12

\[\large r = \sqrt{\dfrac{A}{\pi}}\]

Answer 13

Oh yes, since it depends on A, we say it is a function of A, and write it in function notation like below :

\[\large r(A) = \sqrt{\dfrac{A}{\pi}}\]

Answer 14

ok

Answer 15

we're done !

Answer 16

hold on

Answer 17

a or c was it?

Answer 18

I dont wanna get it wrong so just checing

Answer 19

checking

Answer 20

@Cosmichaotic

Answer 21

are you giving an online exam ?

Answer 22

no its a practice

Answer 23

quiz

Answer 24

fine then :)

Answer 25

cool

Answer 26

wait so a or c?

Answer 27

@ganeshie8

Answer 28

clearly i have failed in explaining properly >.<
tell me why do you it is a or c ?

Answer 29

because your dividing

Answer 30

so its pie over A I know that

Answer 31

You have : \(\large A = \pi r^2\)

Answer 32

divide \(\pi\) both sides, what do you get ?

Answer 33

uhh

Answer 34

its a

Answer 35

then

Answer 36

thats my best guess

Answer 37

I'm not sure if you're able to see the latex code on your end...

Answer 38

if the answer helps -
the correct answer is the last option

Answer 39

ok

Answer 40

pellet

Answer 41

I got a 42 percent

Answer 42

@ganeshie8