How do I find a vertical asymptote

Which function has an inverse that is also a function? a.{(-4,3), (-2, 7), (-1,0), (4, -3), (11, -7)} b.{(-4, 6), (-2, 2), (-1, 6), (4,2), (11, 2)} c.{(-4,5), (-2, 9), (-1,8), (4, 8), (11,4)} d.{(-4,4), (-2, -1), (-1,0), (4, 1), (11, 1)}

The bottom of a vase is a square. each side measury y+11 units. the square has a perimeter of 55 units what is the value of y?

Two less than the quotient of a number and four is less than six. i need the inequality. a. x< 32 b. x< -32 c. x> 16 d. x> -16