Charlie threw a ball up in the air modeled by the function f(x)=−x2+2x+4. Elizabeth release a balloon at the same time, represented by g(x)=2x. At what time do the paths cross and at what height?

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

(a) the volume of the cone is 20/3 in3

hence, option a is correct.