Question

The path traveled by a bottlenose dolphin as it jumps out of water is modeled by the equation y = −0.4x2 + 3x, where y is the height above water and x is the horizontal distance in feet. If a beam of light is shone upward at an angle modeled by the equation x + y = 10, at what height from the water's surface will the beam of light hit the dolphin?
A)2.7 feet

B)3 feet

C)5 feet

D)5.6 feet

Answer 1

We are given the equation of the path traveled by a dolphin expressed as  y = −0.4x2 + 3x and the path of the beam of light expressed on the other hand as x + y = 10. In this case, to know the point of intersection, we equate both equations, that results to x = 5 and y = 5. In this case,the answer is C.