Circles - GRE Subject Test: Math
Card 0 of 2
What is the equation of a circle with center at 
and a radius of 
?
What is the equation of a circle with center at
Step 1: Recall the general equation for a circle (if the vertex is not at 
:
, where center=
Step 2: Recall the shift of the graph..
If the value of 
is positive, it will be shown as a negative shift in the equation.
If the value of 
is negative, it will be shown as a positive shift in the equation.
If the value of 
is positive, it will be shown as a negative shift in the equation.
If the value of 
is negative, it will be shown as a positive shift in the equation.
Step 3: Look at the center given in the problem and find the rule(s) in step 2 that will apply:
Center=
, 
, 
Step 4: Plug in 
into the equation of a circle:
Simplify:
Step 1: Recall the general equation for a circle (if the vertex is not at
Step 2: Recall the shift of the graph..
If the value of
If the value of
If the value of
If the value of
Step 3: Look at the center given in the problem and find the rule(s) in step 2 that will apply:
Center=
Step 4: Plug in
Simplify:
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What is the vertex of the equation of a circle: 
What is the vertex of the equation of a circle:
Step 1: There are no numbers next to 
and 
, so their is no movement of the vertex..
Step 2: Recall the vertex of a circle that does not move...
The vertex of this circle is 
.
Step 1: There are no numbers next to
Step 2: Recall the vertex of a circle that does not move...
The vertex of this circle is
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