Question

arta is solving the equation S = 2πrh + 2πr2 for h. Which should be the result?

StartFraction S Over 2 pi r EndFraction equals h. – r = h
StartFraction S minus r Over 2 pi r EndFraction equals h. = h
S – S minus StartFraction r Over 2 pi EndFraction equals h. = h
S – S minus StartFraction 2 pi Over r EndFraction equals h. = h

Answer 1

Start with S = 2πr h + 2πr^2. Subtract 2πr^2 and solve for h:

S − 2πr^2 = 2πr h
h = (S − 2πr^2)/(2πr) = S/(2πr) − r.

So h = S/(2πr) − r (equivalently (S − 2πr^2)/(2πr)).