Please help me with the following questions.

1.

Find the center of the mass of a thin plate of constant density 8 covering the region bounded by Co the x-axis and the curve y = _ cos x, - - XS 2 4 4Find the length of the following curve. N X= -y from y = 1 to y = 9 N/ W N / - The length of the curve x = 3 y from y = 1 to y = 9 is (Type an exact answer, using radicals as needed.)Find the area of the surface generated by revolving the curve y = OSXs212, about the x-axis. 18 The area of the surface is (Type an exact answer, using it as needed.)