Question 567353
A flag is raised while an onlooker watches from a distance of 21 feet away from the base of the flag pole (see the figure below).
 The flag rises vertically at a rate of 8 inches per second.
Let t denote the time (in seconds) after the flag begins to rise (For simplicity, assume that when the flag begins to rise it is 0 inches above the ground).
 Express the distance d (in feet) between the flag and the onlooker as a function of t.
:
They want this in feet; convert 8" to {{{2/3}}}ft
:
The distance from the onlooker to the flag is the hypotenuse, formed by the 21' from the base of the pole and height of the flag which would be {{{2/3}}}t 
:
d(t) = {{{sqrt(21^2 + ((2/3)t)^2)}}} 
d(t) = {{{sqrt(441 + (4/9)t^2)}}}