The domain is all the numbers of which the inputs can be put. Here, we have a graph, which simplifies things. We just need to look at the x-values of the graph, or the horizontal line. The graph extends both negatively and positively. Thus since the graph extends both ways (right and left) forever, the answer would be D, or all real numbers.
Check the picture below.
keeping in mind that the point of tangency for a radius line and a tangent is alway a right-angle, since the "red" chord is parallel to the "green" tangent line outside, then the chord is cutting the "green" radius there in two equal halves at a right-angle, as you see in the picture.
we know the chord is 10 units long, so 5 + 5, since is perpendicularity with the radius will also cut the chord in two equal halves.
anyhow, all that said, we end up with triangle you see on the right-hand-side, and then we can just use the pythagorean theorem.

Answer: 7
Step-by-step explanation: 5 + 1 + 1 = 7 .
7. d, Julie and randy both walk 5 miles