Observe the graph:
\The circle in the graph is located at second and third quadrants and center is passes through
-axis.
Standard form of circle equation is
, where
is center and
is radius.
Determine which of the below equations are in second and third quadrants and center is passes through
-axis.
Write each equation in standard form.
\Check the sign of
-coordinate is negative and
-coordinate is zero.
\
(a). The circle equation is
.

Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is positive and
-coordinate is zero.
\
(b). The circle equation is
.

Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is negative and
-coordinate is zero.
\
(c). The circle equation is
.
Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is zero and
-coordinate is two.
\
\
(d). The circle equation is
.
Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is negative and
-coordinate is zero.
\
(e). The circle equation is
.
By using completing square method convert the below equations in to standard form of circle.
\
To change expression in to a perfect square trinomials add
to each side of expressions.


Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is negative and
-coordinate is zero.
\
(f). The circle equation is
.





Compare it with standard form of circle equation is
.
\
The
-coordinate of center of the circle is negative and
-coordinate is one.
\
(g). The circle equation is
.




Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is negative and
-coordinate is zero.
\
(h). The circle equation is
.





Compare it with standard form of circle equation is
.

The
-coordinate of center of the circle is negative and
-coordinate is zero.
Possible equations are (b), (d), (e), (g).