Respuesta :

Answer:

128

Step-by-step explanation:

I assume there's a negative sign missing, since the image is a downwards parabola.

f(x) = -x²/256 + 16

The width of the beam is the distance between the x-intercepts.

0 = -x²/256 + 16

x²/256 = 16

x² = 4096

x = ±64

So the width is:

64 − (-64) = 128