See §18.2(vi).
Suggested 2016-07-05 by Adri Olde Daalhuis
Let , , denote the zeros of as function of with
| 18.16.1 | |||
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Then is strictly increasing in and strictly decreasing in ; furthermore, if , then is strictly increasing in .
| 18.16.2 | |||
| , | |||
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| 18.16.3 | |||
| , . | |||
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Also, with defined as in (18.15.5)
| 18.16.4 | |||
| , | |||
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except when .
| 18.16.5 | |||
| , , . | |||
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Let be the th positive zero of the Bessel function (§10.21(i)). Then
| 18.16.6 | ||||
| , | ||||
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| 18.16.7 | ||||
| , . | ||||
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Let . Then as , with () and () fixed,
| 18.16.8 | |||
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uniformly for , where is an arbitrary constant such that .
The zeros of are denoted by , , with
| 18.16.9 | |||
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Also, is again defined by (18.15.17).
For , and with as in §18.16(ii),
| 18.16.10 | |||
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| 18.16.11 | |||
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The constant in (18.16.10) is the best possible since the ratio of the two sides of this inequality tends to 1 as .
For the smallest and largest zeros we have
| 18.16.12 | |||
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| 18.16.13 | |||
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See Driver and Jordaan (2013).
As , with and fixed,
| 18.16.14 | |||
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where is the th negative zero of (§9.9(i)). For three additional terms in this expansion see Gatteschi (2002). Also,
| 18.16.15 | |||
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when .
All zeros of lie in the open interval . In view of the reflection formula, given in Table 18.6.1, we may consider just the positive zeros , . Arrange them in decreasing order:
| 18.16.16 | |||
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Then
| 18.16.17 | |||
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where is the th negative zero of (§9.9(i)), , and as with fixed
| 18.16.18 | |||
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The discriminant (18.2.20) can be given explicitly for classical OP’s.
| 18.16.19 | |||
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| 18.16.20 | |||
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| 18.16.21 | |||
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