# Calculus

posted by Isaac

There is this improper integral problem I've been given. I've completed most of it but still don't understand what I'd get, I don't quite get what it means to go from 'e' to 'infity'. What would I get?

-ln(x)+1/x from 'e' to 'infinity' + -1/x from 'e' to 'infinity'.

1. Steve

technically, it means to evaluate the limit as x->∞, but in practice you can just "substitute" ∞ in for x in the expression.

For example, 1/∞ = 0
e^-∞ = 0
But, ln(∞) = ∞, so that may not help much. It could be that your final value is ∞, or undefined.

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