Originally Posted by

**TcAllen247** I have a practice final and about 10 people in my Calculus class rely on me to help them study for tests, but there is one question I'm stuck on... (might have something with me being absent the day the prof. went over propagated error)

"The instrument used for measuring the height of a cylinder is accurate to the nearest 0.02 cm. The instrument ised for measuring the radius of a cylinder is accurate to the nearest 0.01 cm. A cylinder is measured to have a radius of 6 cm and a height of 20 cm. Use differentials to find (A) the percent error in calculating the surface area and (B) the percent error in calculating the volume of the cylinder."

I know...

(A)

Surface Area = $\displaystyle S=2$$\displaystyle pi$$\displaystyle r^2$$\displaystyle +2$$\displaystyle pi$$\displaystyle rh$

and

(B)

Volume = $\displaystyle V=$$\displaystyle pi$$\displaystyle r^2$$\displaystyle h$

Not really sure where to go from here... I assume solve for one variable (like r for h or h for r then plug in and do the derive... but I'm not 100% and before I tell 10 people the wrong way I want to check!!! Any help would be greatly apperciated!!!

P.S. The final is Wednesday, and we have another study group meeting tonight.