Find the area of the surface when the graph of - V 4 _. is rotated about the x _ axis ( 2 ) for O lt; lt; lt; 1 . ( b ) for 1 lt;...

Hello, I need help with part a of the following problem. Thanks in advance.

Find the area of the surface when the graph of " - V 4 _. "is rotated about the x _ axis( 2 ) for O < < < 1 . ( b ) for 1 < < < 2, and ( 0 ) for 2 = x < 3.