1. Write dy in terms of x and dx if y = 5x2.
2. Determine the linear approximation of 21/2. Express your answer as a reduced fraction in the form a/b.
3. 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.