Which point satisfies both ƒ(x) = 2x and g(x) = 3x?

If sec theta = 5/3 and the terminal point determined by theta is in quadrant 4, then

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

With finding limits of multi variable !