Final answer:
The y-value that the function f(x) is approaching as x approaches 3 from the left is likely associated with the function y = x², as its slope is positive and decreases in magnitude with increasing x.
Step-by-step explanation:
The question refers to finding the limit of a function f(x) as x approaches 3 from the left side. This is a concept from calculus often taught at the high school level, specifically when discussing limits and continuity. Among the given options, assuming they are part of the function under consideration, function b, which corresponds to y = x², would have a positive value for y as x approaches 3, with a slope that is positive and decreasing in magnitude as x increases. This is because the derivative of y = x² is 2x, and as x approaches 3 from the left, the slope (2x) is positive and decreasing in magnitude as compared to values larger than 3.
To determine this, you would evaluate the derivative at values slightly less than 3 to confirm the slope's behavior. With a linear function such as y = 9 + 3x, which has a constant slope of 3, the slope would not decrease as x increases, which does not match the criteria provided in the question.