Answer
The answer is graph (d)
Work Step by Step
This one might be a bit more complicated than the other graphs but it can be solved in three ways:
1) By solving questions 1,3&4 you immediately see that graph (d) is the only one left. This is the elimination process way.
2) By checking the fact that the equation has restrictions ( values not allowed to be used) we can see that (d) is the only graph that has restrictions. By knowing that the radicand ( value under the radical ) cannot be less than zero, we get x is between -3 and 3. Since (d) is the only graph that has restrictions, then its the answer.
3) The third way is by knowing the fact that the equation represents a semi circle. You can deduce that by comparing it to the original equation for a circle (x-a)^{2}+(y-b)^{2}=r^2;where (a,b) are the co-ordinates of the center and r is the radius. Therefore the answer is (d).