We can solve this using the reverse Pythagorean Theorem because we know the diagonal length (hypotenuse) and the length of one side. You should substitute those numbers in as 27^2-15^2=A^2 which, rounded to the nearest inch, is 23 in.
No this is not a function because the x-values repeat. In a function you can have the the output duplicate but not the input. The input at 3 has duplicates s o this is not a function.
