quadratic functions

I need help understanding how to solve these questions'

13. A parking lot is being construCted under a historic hotel. The entrance to the parking lot is through a parabolic arch that is 9 ft high at its centre and 13 Ft wide at its base. :1) Determine a quadratic Function, Mas), that relates the height of: the arch, in Feet, to its width, x, in feet. State the domain of this Function. b) What is the widest vehicle, 6 ft high, that can enter the parking lot through the arch? c) 'What is the tallest vehicle, 6 Ft wide, that can enter the parking lot through the arch? d) Suggest wording for a sign to warn drivers abour the restrictions for vehicles about to enter the parking lot. 15. The owner of a small clothing company wants to create a mathematical model for the company's daily profit, p, in dollars, bas on the selling price, a', in dollars, of the dresses made. The owner has noticed that the maximum daily profit the company has made is $1600. This occurred when the dresses were sold for $75 each. The owner also noticed that selling the dresses for $50 resulted in a prot of $1225. Use a quadratic Function to model this company's daily prot. 6. Determine the quadratic function, in vertex form, that defines each parabola. a) C) 6 M 4 (0, 4) 4 21 (2, 2) 2 (2, 0) (6, 0) X VX 0 0 -4 -2 2 4 -2 4 6 8 -2 -2 -4 -4 -6 -6 b) d) 6 ( 6, 6) 4 4- (2, 4) 2 2 - (-3, 0) (1, 0) X V X 0 O -2 2 4 6 8 -4 -2 2 4 -2 -2 (4, -2) -4 -4 -6 -6