Math
posted by Anonymous .
The standard form of a circle is Ax^2+Cy^2+Dx+Ey+F=0.
Write the equation for the circle:
Center (1,2), point on the circle (2,1).
Okay, I've always put circles in the form (xh)^2+(yk)^2=0. I got this:
r^2=(x1)^2+(y2)^2
then I substitute the point to find the radius:
r^2=(3)^2+(3)^2
r^2=18
So the answer I got is
18=(x1)^2+(y2)^2.
...So what's standard form, and can I change it from my answer to that?
Thx

expand and bring all terms to the left side.
Respond to this Question
Similar Questions

Advanced Math
Write the standard form of the equation of a circle that passes through the points at (0,8) (8,0) and (16,8). Then identify the center and radius of the circle. (x8)^2 + (y8)^2 = 64 (x^2 / 64) + (y^2 / 64) = 64 center=(8,8) radius=8 … 
Math
The points (4, –5) and (– 4, 1) are endpoints of a diameter of a circle. (a) Find the center of the circle. (b) Find the length of the radius of the circle. (Note that this is a distance.) Give the exact answer. Show work. (c) … 
NEED MAJOR HELP! *QUADRATIC EQUATIONS*
Write the equation for the circle with center at ( 8,  6) and radius of 10. (x+8)² + (y + 6)² = 10 (x+8)² + (y + 6)² = 100 (x8)² + (y  6)² = 100 Find the standard equation for the circle with center on the positive xaxis … 
Math
write the equation of the circle in standard form. find the center, radius, intercepts, and graph the circle. x^2+y^26x8y+25=36 
college algebra
write the equation of the circle in standard form find the center radius, intercept and graph circle x^2 +y^2+8x+2y+8=0 
Algerbra
Write the equation of the circle in standard form. Find the center, radius, intercepts, and graph the circle. x2+y2+16x−18y+145=25 Standard form (xh)^2 +(yk)^2 k 
Algebra
2. Write the equation of the circle in standard form. Find the center, radius, intercepts, and graph the circle. x2+y2+8x+2y+8=0 
math
Let the equation of a circle be x^2+y^214x+8y+56 a. Find the standard form of the circle b. Find the center of the circle c. Find the radius of the circle 
Geometry
Write the General form equations for the following circles: 1. A circle with center (1, 6) and radius 4 2. A circle with center (6, 8) and radius 10 3. A circle with center (0, 3) and radius 2√3 4. A circle with center (0.5, 5.5 … 
circles
Convert form standard to general form for circle. Circle with center (a,b) and radius c.