Final Answer:
a) No, the relation \(x = y^2\) does not represent (y) as a function of (x).
b) Yes, the relation \(x^2 + y^2 = 9\) does not represent (y) as a function of (x).
Step-by-step explanation:
a) For a relation to represent \(y\) as a function of \(x\), each \(x\) value should correspond to only one \(y\) value. In the case of \(x = y^2\), for certain \(x\) values, there are two possible \(y\) values (positive and negative square roots), violating the vertical line test. Therefore, the relation \(x = y^2\) does not represent \(y\) as a function of \(x\).
b) The relation \(x^2 + y^2 = 9\) represents a circle centered at the origin with radius 3. For a function, each \(x\) value should correspond to only one \(y\) value. In this case, for each \(x\), there are two corresponding \(y\) values (positive and negative square roots), violating the vertical line test. Hence, the relation \(x^2 + y^2 = 9\) does not represent \(y\) as a function of \(x\).
In conclusion, understanding the concept of functions and applying the vertical line test is crucial to determine whether a relation represents \(y\) as a function of \(x\). The vertical line test helps identify situations where a single \(x\) value maps to multiple \(y\) values, indicating a non-functional relation.