A circle is centered at (3, 8) and is tangent to the x-axis. Write its equation in standard form.

Question

anonymous · Answer

i just need help not the answer

jdoe0001 · Answer

|dw:1386107812164:dw|

we know the center of it, so we just need the radius
notice we are given 2 points already... so what's the distance between (3, 8) and (3, 0) ?  well  $\bf \textit{distance between 2 points}\ \quad \
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\
&(3\quad ,&8)\quad &(3\quad ,&0)
\end{array}\qquad 
d = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}$

jdoe0001 · Answer

http://www.mathwarehouse.com/geometry/circle/images/equation-of-circle/general-formula-equation-of-circle.png

jdoe0001 · Answer

"and is tangent to the x-axis"    <-- meaning is touching it, thus

anonymous · Answer

i got 	
(x - 3)^2 + (y - 8)^2 = 64

anonymous · Answer

is that correct?

jdoe0001 · Answer

yeap

anonymous · Answer

tysm !

jdoe0001 · Answer

yw