how to type a circle equation into graphing calculator

#How to type a circle equation into graphing calculator plus#

Notice we can construct a nice little right triangle here. Really want to, you know, I dislike it when formulasĬonnection to other things.

#How to type a circle equation into graphing calculator plus#

And it becomes, I'll just write this in neutral color, x plus five squared plus y minus five squared is equal to the radius squared, is equal to two, or let me just write

And so this shows forĪny x y that is two away from the center, this equation will hold. The end minus the beginning y minus five, y minus five squared. So the change in y is going to be from this y to that y, this is the end point. So our change in x squared plus our change in y squared, so it's going to be y minus the y coordinate over here, squared is going to be equal to the radius squared. In x between any point x comma y, negative five comma five. It could be an x and y here, and this is going to be two. Well the distance between that coordinate, between any of these x's and y's, it could be an x and y here, And when you plot all of them together, you're going to get aĬircle with radius two around that center. So you want to find all the x's and y's that are two away from it. Negative five comma five, so negative five comma five, and you want to findĪll of the x's and y's that are two away from it. Remember, if you have some center, in this case is the point The Pythagorean Theorem, straight out of the distance formula, which comes out of the I want you to appreciate that this formula comes straight out of This is not just, I don't want you to just memorize this formula. So this right over here tells us that the center of theĬircle is going to be x equals negative five y equals five and the radius is going So I want to rewrite this as, this is x minus negative five, x minus negative five squared, plus y minus positive five, positive five squared is equal to, instead of writing it as four I'll write it as two squared. That equation was x plus five squared plus y minus five squared is equal to four squared. And I really want to hit the point home of what I just did. And the way it's drawn right now, we could drag this out like this, but this the way it's drawn, the radius is indeed equal to two. So that means that the radius is equal to two. So y coordinate is positive five and then the radius squared Cause y minus the yĬoordinate of the center. So the x coordinate must be negative five and the y coordinate

Cause the way we can getĪ positive five here's by subtracting a negative five. So the x coordinate of the center must be negative five.

So x minus the x coordinate of the center. Of the center squared is equal to the radius squared. Of the center squared, plus y minus the y coordinate Want to think about is well what's the center of this equation? Well the standard form of a circle is x minus the x coordinate So it says drag the center pointĪnd perimeter of the circle to graph the equation. On the right hand side? This is actually just the view we use when we're trying to debug Whereas to graph the circle x plus five squared plus y