How do I find the radius of the circle: x^2+y^2-10x-16+73=0

Question

amistre64 · Answer

gotta complete the square to decipher it all

lalaly · Answer

complete the square

anonymous · Answer

complete the square

anonymous · Answer

i think you have to complete the square? has anyone suggested that yet?

amistre64 · Answer

r^2 should be: -73 +(10/2)^2 + (16/2)^2

amistre64 · Answer

more like, complete the "squares" :)

amistre64 · Answer

the basis for completing a square such as:  x^2 +6x +N , where N is some number that "completes the square" can be found in geometry.

take for instance: x^2 + 6x

\begin{array}c
&&&6x/2\
&x^2&x&x&x\
&x&1&2&3\
6x/2&x&4&5&6\
&x&7&8&9\
\end{array}
to fill out a complete square we need to add 9 more parts

amistre64 · Answer

algebraly we complete a square by adding the square of half the number of "x" parts.

x^2 + 4x + N ;   where N=(4/2)^2

x^2 - 3x + N ; where N=(3/2)^2 

x^2 + bx + N ; where N=(b/2)^2