I need help ASAP PLS.​

Monica build a remote control toy airplane for science project to test the plane she launched it from the top of a building the plane travel a horizontal distance of 50 feet before landing on the ground a quadratic function which models the height of the plane in feet relative to the ground at a horizontal distance of x feet from the building is shown

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

Find the domain of the following expression: 1/(√x)-2