anonymous one year ago Write the equation of the circle whose center is at the origin and whose diameter is 12.

1. SolomonZelman

center is at the origin, (that is center at point (0,0), so h=0, k=0) diameter is one half of the radius, so if diameter is 12 then radius is how long? (hope you got this part, and now I will remind you to equation of the circle form) $$\Large\color{black}{ \displaystyle (x-{\bf \color{red}{h}} )^2+ (y-{\bf \color{blue}{k}} )^2 = {\bf \color{green}{r}}^2 }$$ Where 1) $$\large\color{black}{ \displaystyle({\rm \color{red}{h}} ,~{\rm \color{blue}{k}} )}$$ is the $$\normalsize\color{red}{ \bf c\color{blue}{e}n\color{blue}{t}e\color{blue}{r} }$$ of the circle. 2) $$\large\color{black}{ \displaystyle {\rm \color{green}{r}} }$$ is the $$\normalsize\color{green}{ \bf radius }$$ of the circle.

2. anonymous

There is no picture for me to find out what the middle of the circle is!?

3. SolomonZelman

you don't need pics

4. SolomonZelman

do you know how to fill out the $$\large\color{black}{ \displaystyle (x-{\rm \color{red}{h}} )^2+ (y-{\rm \color{blue}{k}} )^2 }$$ ?

5. anonymous

no

6. SolomonZelman

well, your center is (0,0) that means h=0 k=0

7. SolomonZelman

something isn't clear?

8. anonymous

What do you mean!?

9. SolomonZelman

I am asked you if you are confused about something in my explanation? I am asking you that because you don't seem to manage to fill out the left side of the equation of the circle ((( The equation of the circle: $$\large\color{black}{ \displaystyle (x-{\rm \color{red}{h}} )^2+ (y-{\rm \color{blue}{k}} )^2 = {\rm \color{green}{r}}^2 }$$ )))

10. anonymous

Got it thanks!

11. SolomonZelman

oh you got the equation of the circle? ok then...