Refer to Exercise 71. On cloudy days, a better approximation of the sun intensity I is given by If , how many hours after sunrise is ?

.When using a graphing utility (e.g. calculator, graphing software) it's usually best to alter the equation such that y is a function of x. For example: .Now it is in a form more suitable for entering into a graphing utility. Y1 will give you the portion of the graph on top of the x‐axis. Y2 will give you the portion of the graph below the x‐axis Points of Intersection .When the graphs of two equations intersect, in other words, when a point satisfies both equations; this point is called a point of intersection. ‐You can find the point(s) of intersection of two graphs by solving their equations simultaneously Example 5: Finding Points of Intersection .You can begin by sketching the graphs of both equations on the same rectangular coordinate system. This will