What is the coordinate of the center of the circle given by the equation (x-11)^2+(y+22)^2=1?

A. (1,2) B. (11,-22) C. (-11,22) D. (121,484)

Question

What is the coordinate of the center of the circle given by the equation (x-11)^2+(y+22)^2=1?

A. (1,2) B. (11,-22) C. (-11,22) D. (121,484)

anonymous · Answer

@zepdrix

zepdrix · Answer

The general form of a circle is given by:$$\Large\rm (x-h)^2+(y-k)^2=r^2$$With radius $\Large\rm r$ and center $\Large\rm (h,k)$

zepdrix · Answer

See how the general form has subtraction next to each x and y?
We need that subtraction so we can accurately determine the coordinate of the center.

anonymous · Answer

ok

zepdrix · Answer

$$\Large\rm (x-11)^2+(y+22)^2=1$$So if we want subtracting with our y....
we can maybe write it like, minus a negative, that's the same as a positive,$$\Large\rm (x-11)^2+(y-[-22])^2=1$$

zepdrix · Answer

I hope it's not too confusing doing it that way >.<
Maybe an easier way too remember would be...
you always want the opposite sign of whatever you see in the brackets.

Since it's x-11, our x coordinate of the center will be 11.

zepdrix · Answer

Since it's y+22, our y coordinate will be -22.

zepdrix · Answer

That make... some sense...? >.< heh

anonymous · Answer

yes it makes complete since your awesome! thank you!

anonymous · Answer

sense*

zepdrix · Answer

lol np :3