Answer:
Not a function
Explanation:
A function is a special type of relationship where each input (x-value) is related to exactly one output (y-value).
To determine whether the relationship y² + x² = 35 represents a function, we can solve the equation for y:

Here, the presence of the ± sign in front of the square root indicates that for some x-values there are two corresponding y-values, which does not conform to the definition of a function.
The vertical line test is a visual method for confirming whether a graph represents a valid function. If a vertical line intersects the graph at more than one point for any x-value in the domain, the graph fails the test and does not represent a valid function.
The graph of the given relationship is a circle centered at the origin (0, 0) with a radius of √(35) units. It fails the vertical line test since a vertical line intersects the graph at more than one point for any x-value in the domain except the leftmost and rightmost x-values.
Therefore, based on both algebraic analysis and the vertical line test, the relation y² + x² = 35 does not represent a function because there are x-values for which there are multiple y-values, and its graph fails the vertical line test.