Skalarprodukt Dr. F. Raemy
Beweis der Gleichheit der Definitionen des Skalarproduktes
Skizze
Definition: ! =!("
a;"
b) zu!zeigen: "
a""
b!!=2)!! "
a " "
b cos!!!=1)!!axbx+ayby
Beweis!1) :
"
a= ax ay
#
$%
&
'( =ax"
i +ay"
j ; "
b= bx by
#
$%
&
'( =bx"
i +by"
j
) "
a""
b = ax"
i +ay"
(
j)
"(
bx"i +by"j)
=axbx+aybyBeweis!2)
"
a= ax ay
#
$%
&
'( = a!cos* a!sin*
#
$%
&
'( ; "
b= bx by
#
$%
&
'( = b!cos+ b!sin+
#
$%
&
'(
)a"""
b = a!cos* a!sin*
#
$%
&
'(" b!cos+
b!sin+
#
$%
&
'( =ab
(
cos* cos++sin* sin+)
) "
a""
b =abcos