Read this partial summary of Passage 1. it has been known since ancient times that
people behave oddly when the moon is full. The
moon's gravity may be the cause.
Which sentence could be added to complete the
summary?

what do you mean.

do we have to write a essay?

. a function is a relation in which each input has only one output. in the relation , y is a function of x, because for each input x (1, 2, 3, or 0), there is only one output y. x is not a function of y, because the input y = 3 has multiple outputs: x = 1 and x = 2.