. ( ).
- (sin, cos).
15) . . . .
, f(x)=f(-x).
, f(x)=-f(-x).
, , , . ( )
(). ( )
. ( )
16) . . =f(kx) y=f(x). .
f(x) , f(x-t)=f(x+t).
.
f(), \k, k ú0, f(k).
-:
f(x)=f(x+t) (1)
F(kx)=f(k(x+P)) (2)
=kx, (1): F(kx)=f(kx+t) (1) (2) , :
f(kx+T)=F(k(x+P))
kx+T= k(x+P)
P=T/k
...
. . . .
f(x) , f(x-t)=f(x+t).
f(x) g(x) , , , . ( , , ).
-. ( ).
.
. . . .
, , , , .
|
<=
x|+|y|$|x+y|
|x|-|y|#|x+y|
|xy|=|x||y|
|1\x|=1\|x|
, . n- .
, : an=an-1+d, d .
.