Some tricky diff problems

Hi I have a some problems I could use help working through, if anyone could help me out here Id be v greatful!!

(1)

$\displaystyle

\int {\frac{{dx}}

{{\sqrt {4x^2 - 9} }}}

$

(hyperbolic function)

(2)

$\displaystyle

\oint\limits_r {\{ (x^2 - y)dx + (y^2 + x)dy\} }

$

Where r is the closed path, mapped counterclockwise, described by the square with verticies at (0,0),(1,0),(1,1),(0,1)

(3)

- use greens theorem to evaluate

$\displaystyle

\oint\limits_r {\{ (y\exp [x^2 y^2 ] - y)dx + (x\exp [x^2 y^2 ] + x)dy\} }

$

where r, mapped counterclockwise, is the circle of th radius a with centre at the origin.