Final answer:
To show that if Limx→∞f(x)=1, then ∫a÷∞f(x)dx diverges, you can use the limit comparison test.
Step-by-step explanation:
To show that if Limx→∞f(x)=1, then ∫a÷∞f(x)dx diverges, you can use the limit comparison test. First, rewrite the integral as ∫a÷∞(x-1+1)dx. Next, take the limit of the quotient f(x)/g(x) as x→∞, where g(x) = x-1. If the limit is a positive finite number, then both integrals converge or both integrals diverge. Since the limit is equal to 1, the integral ∫a÷∞(x-1+1)dx diverges.