# Full text of "Scientific Papers - Vi"

## See other formats

```170
ON  THE PASSAGE  OF  WAVES  THEOUGH
since the last two integrals cancel, as appears when we write TT  n being even.    .
In (35)
\ sinn ((f) + a) + £ sin71 (<j>  a) = sin'1 \$ cosw a
tfi   fi  j
"*'-7Ğr~" si11'1""2 ^ cos2 <£ sin2 a cos91"2 a JL , ^
+ -
n.ğ-l.n-2.ji-3
sinn~4 (j) cos4 <£ sin4 at cosn~4Ğ + . . . + cosn <f> sinn a, (
and thus the result may be expressed by means of the integrals A.
if n = 2,
(35) = 4 I    cZ</> sin2 </!> {sin2 <p cos2 a 4- cos2 <£ sin2 a} log (2 sin 0)
J o
= 4 f (cos2 a  sin2 a) /i4 4- sin2 a A}...............................(
I \                                     y        ğ                            Ğ;                                                                            \
(35) = 41    <iĞA sin4 d> {sin4 rf> cos4 a + 6 sin2 cf> cos2 </> sin3 a cos2 a Jo
+ cos4 ^ sin4 a} log (2 sin 0) = 4 {(cos4 a  6 sin2 a cos2 a -f- sin4 a) /i8
+ (6 sin2 a cos2 a  2 sin4 a) &6 4- sin4 a h4].............(.
(35) = 4, {(cos6 a  15 cos4 a sin2 a + 15 cos2 a sin4 a  sin8 a) hlz -f (15 cos4 a sin2 a  30 cos2 a sin4 a + 3 sin6 a) h10 + (15 cos2 a sin4Ğ  3 sin6 a) A8 + sin8Ğ A6}.....................(.
It is worthy of remark that if we neglect the small differences be1 the tis in (39), it reduces to 4cos6Ğ/t:2J and similarly in other cases.
When n is much higher than 6, the general expressions correspond! (37), (38), (39) become complicated. If, however, cos a be either 0, 01 (36) reduces to a single term, viz., cos'3' <£ or sinn <£. Thus at the Q (cos a = 0) from either of its forms
On the other hand, at the edges (cos a = ħ 1)
\_    [^                                                       '
Jo
In (30), the object of our quest, the integral (35) occurs with the coeff
22.42.62...n2.........................^ (0 + a) log (2 sin <£).
```