I appreciate any help on the following problems:

1.) Find the area by double integration in polar coordinates inside circles r = 1 and r = 2sinΘ

2.) Use double integration in polar coordinates to find the volume of solid that lies below given surface and above plane region R bounded by given curve: z=x^2 +y^2 and r=2cosΘ

3.) Evaluate the given integral by first converting to polar coordinates: 1/(1+x^2 +y^2) dxdy where x is defined over region between 0 and (1-y^2)^1/2 and y is defined over region between 0 and 1.