In a function, each x value must have a singular y value. This means that one x-value (the values on the left) may not have a line pointing to 2 different y-values (the values on the right). In the first relation, the x-value of 6 points to both 4 and 6. This means that the value repeats, and in a function x-values cannot repeat.
However, y-values can repeat. So, situations like that seen in D, where both the x-values of 2 and 4 equal the y-value of 6 are fine.
Using a^2+b^2=c^2we can substitute a and b in which is 34^2+8^2=c^21156+64=c^21220 = c^2Now we need to square both sides√1220 = √c^234.9284983931 ----> 34.9334.93 = cc = 34.93
