please answer my last question i'm struggling could really use some help (trigonometry) its marked highly lots of points

4. find the geometric mean of 4 and 12. 24 8

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.