Final answer:
The convergent integrals are ∫(0 to ∞) e^(-x) dx and ∫(-∞ to ∞) x^2 dx.
Step-by-step explanation:
To determine which integrals are convergent, we need to evaluate each integral and see if the result is a finite number.
a) The integral ∫(0 to ∞) e^(-x) dx can be evaluated using integration by parts and will converge to 1.
b) The integral ∫(1 to ∞) 1/x dx can be evaluated as ln(x) from 1 to ∞ which diverges to infinity.
c) The integral ∫(-∞ to ∞) x^2 dx is a definite integral and the result will be a finite number.
d) The integral ∫(0 to 1) 1/x dx can be evaluated as ln(x) from 0 to 1 which diverges to negative infinity.
Therefore, the integrals that are convergent are a) and c).