approximate the change in the lateral surface area(excluding the area of the base of a right circular cone of fixed height of h=6m when its radius decreases from r=11m to r=10.9m

Question

S=(pi)r sqrt(r^2+h^2)

Answer 1

gee - you have the function. Plug and chug.

s = πr√(r^2+h^2)
ds = π(2r^2+h^2)/√(r^2+h^2) dr

Now just plug in the numbers, using -0.1 as dr