Question

Graph the circle with center at (3, -2), which also passes through the point (0,2). Label the center and at least four points on the circle. Write the equation of the circle.

Answer 1

Hi,id love to help but I am not doing it for you.

What are you confused about?
What are you stuck on?

Answer 2

Try thinking about what you have here. The centre, a point on the circle. What can you find using that information?

Answer 3

u can find distance right

Answer 4

@JFlaus

Answer 5

Exactly, and what's another way of saying the distance between the centre and a point on the circle?

Answer 6

center?

Answer 7

What do you mean?

Answer 8

the center of the circle

Answer 9

Yes, we have the centre of the circle and a point on the circle. So from that we can get the radius right? :)

Answer 10

mmhm so i need to do the distance formula first

Answer 11

@JFlaus

Answer 12

Yes, ultimately our goal is to get the equation of the circle right? And for that we can use the equation formula which requires us to have things like radius :) So were workig them out from what we've been given :)

Answer 13

ok ill do the distance formula and find that out ill tag u when i get it

Answer 14

@JFlaus it says 5 is the distance

Answer 15

Sounds good, so tell me all the stuff we know about this circle.

Answer 16

we know both points and the center

Answer 17

Good, so tell me what the formula for equation of a circle is.

Answer 18

(x−h)2+(y−k)2=

Answer 19

@JFlaus

Answer 20

= r^2

Answer 21

So we take the formula (x-h)^2+(y-k)^2=r^2 and we sub in what we have. So what do h and k refer to? :)

Answer 22

ik h is height i forgot what k is

Answer 23

Not quite. H would be height in another question, but in this formula you take the centre point as (h,k) :)

Answer 24

So if the centre is (3, -2) then h = 3 and k = -2 :)

Answer 25

ok so now i just plug it in? @JFlaus

Answer 26

Yup :) And thatll give you the equation of the circle :)

Answer 27

(x−3)2+(y−-2)2= R^2 ?

Answer 28

Now solve it out :)

Answer 29

wait isnt R=5

Answer 30

Yeah r was 5 so we sub it in and square it :)

Answer 31

ok so whats the formula completly

Answer 32

@JFlaus

Answer 33

The formula is (x-h)^2+(y-k)^2=r^2 :)

Answer 34

ok and do i just graph that

Answer 35

@JFlaus sorry last question ^

Answer 36

( X-3)^2 + (Y +2 )^2= 5^2

Answer 37

No, when you simplify that out you get the equation of the circle and thats your answer isnt it? :P

Answer 38

im lost

Answer 39

@JFlaus

Answer 40

The question asks you to find the equation of the circle right? :)

Answer 41

yes how would u simplfy this

Answer 42

You take the formula and you sub in for h and k and r and then you simplify it :)