3/4 ploted on a number line

Ahovercraft takes off from a platform. its height (in meters), xx seconds after takeoff, is modeled by: h(x)=-2x^2+20x+48h(x)=−2x 2 +20x+48 what is the maximum height that the hovercraft will reach?

What is the output, or dependent variable of quantity? 1: x 2: f(x) 3: y

A. 15 degrees b. 45 degrees c. 30 degrees d. 60 degrees