# Check the equation of the circle

1. Mar 27, 2005

### aisha

check plz the equation of the circle

the Center is C(-1,2) and the x intercept is 3

I found the distance between the center and the point to be r^2=10

and the midpoint of the two given points to be (1,1)

therefore my final equation for this circle is

$$(x-1)^2 + (y-1)^2 =10$$

is my answer correct? Any objections? :tongue2:

Another question Equation of a circle with center (4,-3) that passes through the point (2,1)

for this question I got $$(x-4)^2 + (y+3)^2 =20$$

Is this one right?

Last edited: Mar 27, 2005
2. Mar 27, 2005

### Data

Unfortunately not quite. You don't need to find any midpoint at all: the center is given.

Also I don't like your radius. It should just be the distance between the two given points (which I calculate to be $\sqrt{20}$).

3. Mar 27, 2005

### Data

4. Mar 27, 2005

### aisha

oops ok I got my new answer to be

$$(x+1)^2 + (y-2)^2 = 20$$

is this correct now can you also check the second question in the first post?

5. Mar 27, 2005

### Data

Yep, they're both right now.