Without any further information, my best guess would be that this is a typo and exercise a) is supposed to read "draw f(x)". Unless, of course, g(x) is defined somewhere else.

To draw the function f(x), you can go to Wolfram Alpha at http://www.wolframalpha.com and type in the function in Mathematica syntax, or just click here:

http://www.wolframalpha.com/input/?i=Piecewise[{{Sqrt[1-x]%2Cx<%3D1}%2C{.5x-2%2Cx>1}}]