Question

If the relative error in measuring the radius of a circular plane is α, find the relative error measuring its area.

Answer 1

Given that

\(\frac{\Delta r}{r} = a\) (if let r is radius)

\(\frac{\Delta A}{A} = ?\) (if let A is area of circle)

We know that the area of a circle(A) = πr² then

we know that if there is a little approximation in variables then,