# calc: relative error

posted by
**amanda** on
.

The circumference of a sphere was measured to be 77 cm with a possible error of .8 cm.

Use differentials to estimate the maximum error in the calculated surface area.

Estimate the relative error in the calculated surface area.

please help me..thank you!

Area= 4 PI radius^2

dA= 8 PI radius dR

What is your difficulty with this?

well to be quite honest i am still not sure how to solve the two questions. i tried taking the derivative of the surface area and multiplying by .8 but this is not the correct answer.i know that the radius is is 77/2pi but could u elaborate more? thanks