Another way to identify the domain and range of functions is by using graphs. Because the domain refers to the set of possible input values, the domain of a graph consists of all the input values shown on the x-axis. The range is the set of possible output values, which are shown on the y-axis
Domain = looking for the very far left value and the very far right value on the x-axis, and only x-axis, so the farthest left x-axis value and the farthest right x-axis value.
Range = very bottom y-value, and very top y-value
In both cases, if the arrows extend forever then that means you could have the value of infinity.
We are asked for the distance between the man and the horizon The straight line from the man to the horizon is a tangent line to the surface of the earth Using Pythagorean theorem (3.7 + 3959)² = 3959² + d²