Question

A parabolic listening device is shaped such that the depth of the bowl depends on its radius and can be represented by the curve D(r) = 0.145r2. What is the radius when the depth is 8 inches? Round to the nearest thousandth of an inch

Answer 1

The correct answer is C, or 7.428 inches

Just got it right on edge 2020, hope this helps!! :)

Answer 2

The correct answer: 7.428 inches


Step-by-step explanation:

Given the equation is D(r) = 0.145r^2

Where D is the depth and r is the radius
Putting D = 8 inches in the equation

8 = 55.2

r^2= 8/ 0.145

r^2 = 55.2

R^2= 7.428 inches


The radius of depth is 7.428 inche



Hope this help you : )