I am getting a negative number for the area of a semicircle, and I can't find my mistake.
find: area of semi-circle of radius 2, centered at origin.
A=S-22S0sq rt(4-x2)dydx,
[i.e. limits of x are -2 and 2, limits of y are 0 and square root (4-x2)]
1st int.
A=S-22sq rt (4-x2)dx
change...