Final answer:
To determine the fundamental set, we need to check if the given functions satisfy the differential equation. Option E is a fundamental set.
Step-by-step explanation:
To determine which of the sets is also a fundamental set, we need to check if the given functions satisfy the differential equation y'' - 2y' + y = 0.
Let's start with option A: {te^t, t^2e^t}. Taking the second derivative of t^2e^t, we get (2t + 2)e^t, which doesn't match with the -2y' term in the differential equation. Therefore, option A is not a fundamental set.
By using the same approach, we can also find that options B, C, D, and F are not fundamental sets.
Finally, let's check option E: {e^t - te^t, e^t + te^t}. Taking the derivatives of e^t - te^t and e^t + te^t, we find that they satisfy the differential equation. Therefore, option E is a fundamental set.