Answer:
No. The equation x² + y² = 7 does not define y as a function of x.
Explanation:
The equation of a circle is:

where:
- (x, y) is a point on the circle.
- (h, k) is the center.
- r is the radius.
From observation of the given equation, x² + y² = 7, we can see it represents a circle centered at the origin (0, 0) with a radius of √7.
In a function, for each x-value, there should be a unique y-value.
In the case of a circle, there are two possible y-values for each x-value due to the positive and negative square root.
Therefore, the given equation x² + y² = 7 does not define y as a function of x because it is a circle, and for each x-value there are two possible y-values.