Like what you saw?
Create FREE Account and:
 Watch all FREE content in 21 subjects(388 videos for 23 hours)
 FREE advice on how to get better grades at school from an expert
 Attend and watch FREE live webinar on useful topics
The Circle  Problem 1
FREECarl Horowitz
Carl Horowitz
University of Michigan
Runs his own tutoring company
Carl taught upperlevel math in several schools and currently runs his own tutoring company. He bets that no one can beat his love for intensive outdoor activities!
Given the coordinates of center of a circle (h, k) and the radius (r), plug the values into the general equation of a circle: r^2 = (xh)^2 + (yk)^2. Be careful to change the signs accordingly when plugging in the values for h and k.
Finding the equation for a circle with a specified center and radius. So really all we have to do when we're looking for the equation for a circle is look for our general equation.
So our equation is just r² is equal to x minus 8² plus y minus k² where h and k are the coordinates of the center, so really all we have to do is take the information we're given and plug it in.
So our radius is 5, so we go to our r plug in 5, 5² is easy enough to do, we end up with 25 is equal to x minus h, h is the coordinate of our center so we go to our 1, plug that in and we end up with x minus 1, x plus 1 and then add it to do the same thing for the y coordinate of the center plugging in 2 for k and we end with y minus 2 quantity squared.
So really to find the equation of a circle all we have to do is remember the general formula and then plug in all the information.
Please enter your name.
Are you sure you want to delete this comment?
Carl Horowitz
B.S. in Mathematics University of Michigan
He knows how to make difficult math concepts easy for everyone to understand. He speaks at a steady pace and his stepbystep explanations are easy to follow.
i love you you are the best, ive spent 3 hours trying to understand probability and this is making sense now finally”
BRIGHTSTORM IS A REVOLUTION !!!”
because of you i ve got a 100/100 in my test thanks”
Concept (1)
Sample Problems (11)
Need help with a problem?
Watch expert teachers solve similar problems.

The Circle
Problem 1 12,909 viewsEquation for a circle centered at (1,2) with radius 5.

The Circle
Problem 2 10,165 viewsGive the center and radius of the circle defined by
2(x − 4)² + 2(y − 1)² = 72 
The Circle
Problem 3 9,549 viewsGive the center and radius of the circle defined by
x² + y² + 6y − 2x − 15 = 0 
The Circle
Problem 4 9,474 viewsFind the equation of a circle that has a diameter with endpoints at (3,1) and (5,5).

The Circle
Problem 5 1,567 views 
The Circle
Problem 6 1,424 views 
The Circle
Problem 7 1,399 views 
The Circle
Problem 8 1,359 views 
The Circle
Problem 9 1,407 views 
The Circle
Problem 10 1,398 views 
The Circle
Problem 11 1,350 views
Comments (0)
Please Sign in or Sign up to add your comment.
·
Delete