Finding the radius of a Circle Touching a Parabola and the Axis
I have a little problem with a question:
What is the radius of a a circle that touches the parabola 1/2x² at (2,2) and the x-axis?
Here the derivative of our parabola is y=x
And if we get
This could give us the common point between those two circles; that would be the center of the circle that we want.
But this gives me a strange equation, that I really don't know what it is for.
Get the center (a,b)
and use it at the circle equation.
But where does (2,2) enters here?
I saw something about using both at the same equation, like:
Is this possible? Aren't x and y fixed values here?
Thanks! I can't find a good source to research on this.