Answer:
Step-by-step explanation:
The paths crossed at when the height are equal i.e when f(x) = g(x)
Given
f(x)=−x^2+2x+4
g(x) = 2x
IF f(x) = g(x), then;
−x^2+2x+4 = 2x
−x^2+2x+4 - 2x = 0
−x^2+4 = 0
-x^2 = -4
x^2 = 4
x = ±√4
x = 2 and -2
Time cannot be negative
Hence x = 2
The path crossed after 2 seconds