Thread: Simple Interval finding?

I've done problems exactly like these, but these two keep giving me the wrong answer, and I'm not sure why.

1) if |x - 2| < delta then |1/x - 0.5| < 0.2
2) if |x - 4| < delta then |sqrt(x) - 2| < 0.4

In both I need to find delta.

Originally Posted by CFem

I've done problems exactly like these, but these two keep giving me the wrong answer, and I'm not sure why.

1) if |x - 2| < delta then |1/x - 0.5| < 0.2
2) if |x - 4| < delta then |sqrt(x) - 2| < 0.4

In both I need to find delta.

For 2.

Try multiplying by its conjugate.

Notice that





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So





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So .