What is the value of S4 for

A 1/9
B 7/54
C 5/27
D 10/27

Is each relation a function? if so, state whether it is one-to-one or many-to-one. 3. (-4,7), (-3,5), (1,4), (3,-8), (5,-11) 4. (-4,8), (-2,4), (0,1), (2,4), (4,8) 5. (-2, 1), (-2,3), (0,-3), (1,4), (3,1)

Me. i can't figure out this question. give an explanation too. .

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.