Give the Domain and Range of H={(-2,-3),(5,9),(5,-2)}
Write your answer using set notations

The domain is the set of possible x values or inputs. We list each unique x value once (ignoring any repeats)

The range is the set of possible y outputs. Convention is to sort the values from smallest to largest.

This relation is not a function because the x value x = 5 corresponds to multiple y values.

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4