The measurement of the side of a square is found to be 12 cm with a possible error of 0.05 cm. Use differentials to estimate the propagated error ΔA in computing the area of the square. Please do not include the ± symbol in your answer. Round your final answer to one decimal place.

Answer 1

A = x^2
A + dA = (x+dx)^2 = x^2 + 2 x dx + dx^2
if dx is small
A + dA = x^2 + 2 x dx
so
dA = 2 x dx