Question

evaluate the integral from [-2,2] sqrt(4-x^2)dx

Answer 1

\[2\pi\]

Answer 2

method is to think that
\[y=\sqrt{4-x^2}\] is the upper half of a semicircle of radius 2. area of a circle of radius 2 is
\[4\pi\] and half of that is
\[2\pi\]