Given a(1,7) b(8,4) and c(3,10) which coordinates will make line AB parallel to line CD

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

The bake stars picked 907 apples last weekend at a local orchard they made caramel apples and sold them in the bakery in trays of 6

Which is f(5) for the function –2x2 + 2x - 3?