given the center (h,k) and radius r=3, write an equation for the circle in standard form
a) (x+5)^2+y^2=9
b) (x-5)^2+y^2=9
c) (x-5)^2+y^2=3

Question

given the center (h,k) and radius r=3, write an equation for the circle in standard form
a) (x+5)^2+y^2=9
b) (x-5)^2+y^2=9
c) (x-5)^2+y^2=3

solomonzelman · Answer

The equation of a circle is:
$\large\color{black}{ \displaystyle (x-{\rm \color{red}{h}} )^2+ (y-{\rm \color{blue}{k}} )^2 = {\rm \color{green}{r}}^2 }$ 

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.

solomonzelman · Answer

this is the general form, and you don't even need to change the (h,k).
All you need to do is to substitute 3 for $\rm \color{green}{r}$.

solomonzelman · Answer

you have some typos in a question apparently....

anonymous · Answer

its B ?  i forgot to put that (h,k)=(5,0)

solomonzelman · Answer

ok,

h=5
k=0
r=3

then, yes, option B is correct.

(x-5)²+y²=9

solomonzelman · Answer

questions?

anonymous · Answer

no thank you !

solomonzelman · Answer

Alright! You are welcome; have a good luck!