Can some one please help me with this? Please explain how you got the answer so I can understand how to do it alone.. ):

Question

anonymous · Answer

A toy rocket was launched from the ground. The function f(x) = -16x2 + 256x shows the height of the rocket f(x), in feet, from the ground at time x seconds.
What is the axis of symmetry of the graph of f(x), and what does it represent? 

 		x = 8; it takes 8 seconds to reach the maximum height and 8 seconds to fall back to the ground
	
x = 16; it takes 16 seconds to reach the maximum height and 16 seconds to fall back to the ground
	
x = 8; it takes 8 seconds to reach the maximum height and 16 seconds to fall back to the ground

	x = 16, it takes 16 seconds to reach the maximum height and 32 seconds to fall back to the ground

anonymous · Answer

Well, you have $$f(x)=-16x^{2}+256x$$ What do graphs of $$g(x)=x^{2}$$ look like? Just worry about the g(x) for now.