• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

Fast calculus help

thesurge

Golden Member
A child 6 ft tall walks at a rate of 6 ft/sec toward a lightpole that is 22 ft above the ground. At what rate is the length of his shadow (x+y) changing when he is 36 ft (y) from the base of the light.

I got 9/4 ft./sec. Can anyone check?

edit:
steps
\frac{x+y}{22}=\frac{x}{6}
y=\frac{8}{3} \times x

d/dt(y)=d/dt(\frac{8}{3} \times x)

6=8/3 dx/dt
dx/dt=9/4
 
Originally posted by: RapidSnail
A six foot tall child?

In math facts do not have to be logical just the steps to solve for the answer.
If you want logical facts try an applied math.
 
Back
Top