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### Zero in the numerator

If in a fraction the numerator is **zero** and the denominator is unequal zero, the result is zero. That we learned already in school.

##### Explanation

You can check that

The fraction

gives the same result, but you cannot check it, as there is no ∞ key on your calculator. Infinity is not a number. Yet, we think the result is quite logic. Now we investigate what the fraction

will produce. We know that Δ*x* approaches zero, but it is not zero, and therefore the division is permitted. So the answer must be 0. Yet again, you cannot check it, as there is no Δ*x* key on your calculator.