How do you find the equation of the circle given Radius 3 and Tangent to y-axis at (0,4)?

1 Answer
Douglas K.
Nov 5, 2016

There is not enough information to uniquely solve this problem. Please see the explanation.

Explanation:

The phrase, "Tangent to the y-axis at #(0,4)#", tells us that the y coordinate of the center is 4. The phrase "given radius 3" tells us that the x coordinate of the center can be either -3 or 3 but there is no way to know which. Therefore, the equation of the circle is either:

#(x - -3)^2 + (y - 4)^2 = 3^2# or #(x - 3)^2 + (y - 4)^2 = 3^2#

Related questions
See all questions in General Form of the Equation
Impact of this question
2747 views around the world
You can reuse this answer
Creative Commons License