Solve the problem.
-Wind speed varies in the first twenty meters above the ground. For a particular day, let f(x) = 2.1 lnx + 3.1 compute the wind speed x meters above the ground. At what height is the wind speed 5 meters per second?
Round results to the nearest hundredth.
A) 2.46 m
B) 0.40 m
C) 0.90 m
D) 1.22 m

Question

Quizplus · Accepted Answer

To find the height at which the wind speed is 5 meters per second, set the function equal to 5 and solve for x: 5 = 2.1ln(x) + 3.1. Subtract 3.1 from both sides to get 1.9 = 2.1ln(x), then divide by 2.1 to get ln(x) = 0.90476. Solve for x by taking the exponential of both sides, resulting in x ≈ 2.47, which rounds to 2.46 meters.

Solve the Problem. -Wind Speed Varies in the First Twenty Meters Above the Meters