Trigonometrie Beispiele
cos(6x)cos(6x)
Schritt 1
Eine gute Methode cos(6x)cos(6x) zu entwickeln, ist die Anwendung des Satzes von de Moivre (r(cos(x)+i⋅sin(x))n=rn(cos(nx)+i⋅sin(nx)))(r(cos(x)+i⋅sin(x))n=rn(cos(nx)+i⋅sin(nx))). Wenn r=1r=1, cos(nx)+i⋅sin(nx)=(cos(x)+i⋅sin(x))ncos(nx)+i⋅sin(nx)=(cos(x)+i⋅sin(x))n.
cos(nx)+i⋅sin(nx)=(cos(x)+i⋅sin(x))ncos(nx)+i⋅sin(nx)=(cos(x)+i⋅sin(x))n
Schritt 2
Multipliziere die rechte Seite der Gleichung cos(nx)+i⋅sin(nx)=(cos(x)+i⋅sin(x))ncos(nx)+i⋅sin(nx)=(cos(x)+i⋅sin(x))n durch Anwenden des binomischen Lehrsatzes aus.
Multipliziere aus: (cos(x)+i⋅sin(x))6(cos(x)+i⋅sin(x))6
Schritt 3
Wende den binomischen Lehrsatz an.
cos6(x)+6cos5(x)(isin(x))+15cos4(x)(isin(x))2+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)(isin(x))+15cos4(x)(isin(x))2+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4
Schritt 4.1
Vereinfache jeden Term.
Schritt 4.1.1
Wende die Produktregel auf isin(x)isin(x) an.
cos6(x)+6cos5(x)isin(x)+15cos4(x)(i2sin2(x))+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)+15cos4(x)(i2sin2(x))+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.2
Schreibe neu unter Anwendung des Kommutativgesetzes der Multiplikation.
cos6(x)+6cos5(x)isin(x)+15⋅i2cos4(x)sin2(x)+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)+15⋅i2cos4(x)sin2(x)+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.3
Schreibe i2i2 als -1−1 um.
cos6(x)+6cos5(x)isin(x)+15⋅-1cos4(x)sin2(x)+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)+15⋅−1cos4(x)sin2(x)+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.4
Mutltipliziere 1515 mit -1−1.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)+20cos3(x)(isin(x))3+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.5
Wende die Produktregel auf isin(x)isin(x) an.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)+20cos3(x)(i3sin3(x))+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)+20cos3(x)(i3sin3(x))+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.6
Schreibe neu unter Anwendung des Kommutativgesetzes der Multiplikation.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)+20⋅i3cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)+20⋅i3cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.7
Faktorisiere i2i2 aus.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)+20⋅(i2⋅i)cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)+20⋅(i2⋅i)cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.8
Schreibe i2i2 als -1−1 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)+20⋅(-1⋅i)cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)+20⋅(−1⋅i)cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.9
Schreibe -1i−1i als -i−i um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)+20⋅(-i)cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)+20⋅(−i)cos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.10
Mutltipliziere -1−1 mit 2020.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)(isin(x))4+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.11
Wende die Produktregel auf isin(x)isin(x) an.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)(i4sin4(x))+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)(i4sin4(x))+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.12
Schreibe neu unter Anwendung des Kommutativgesetzes der Multiplikation.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15⋅i4cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15⋅i4cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.13
Schreibe i4i4 als 11 um.
Schritt 4.1.13.1
Schreibe i4i4 als (i2)2(i2)2 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15⋅(i2)2cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15⋅(i2)2cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.13.2
Schreibe i2i2 als -1−1 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15⋅(-1)2cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15⋅(−1)2cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.13.3
Potenziere -1−1 mit 22.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15⋅1cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15⋅1cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15⋅1cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15⋅1cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.14
Mutltipliziere 1515 mit 11.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(isin(x))5+(isin(x))6
Schritt 4.1.15
Wende die Produktregel auf isin(x)isin(x) an.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(i5sin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(i5sin5(x))+(isin(x))6
Schritt 4.1.16
Faktorisiere i4i4 aus.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(i4isin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(i4isin5(x))+(isin(x))6
Schritt 4.1.17
Schreibe i4i4 als 11 um.
Schritt 4.1.17.1
Schreibe i4i4 als (i2)2(i2)2 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)((i2)2isin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)((i2)2isin5(x))+(isin(x))6
Schritt 4.1.17.2
Schreibe i2i2 als -1−1 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)((-1)2isin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)((−1)2isin5(x))+(isin(x))6
Schritt 4.1.17.3
Potenziere -1−1 mit 22.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(1isin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(1isin5(x))+(isin(x))6
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(1isin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(1isin5(x))+(isin(x))6
Schritt 4.1.18
Mutltipliziere ii mit 11.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(isin5(x))+(isin(x))6cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)(isin5(x))+(isin(x))6
Schritt 4.1.19
Wende die Produktregel auf isin(x)isin(x) an.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+i6sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+i6sin6(x)
Schritt 4.1.20
Faktorisiere i4i4 aus.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+i4i2sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+i4i2sin6(x)
Schritt 4.1.21
Schreibe i4i4 als 11 um.
Schritt 4.1.21.1
Schreibe i4i4 als (i2)2(i2)2 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+(i2)2i2sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+(i2)2i2sin6(x)
Schritt 4.1.21.2
Schreibe i2i2 als -1−1 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+(-1)2i2sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+(−1)2i2sin6(x)
Schritt 4.1.21.3
Potenziere -1−1 mit 22.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+1i2sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+1i2sin6(x)
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+1i2sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+1i2sin6(x)
Schritt 4.1.22
Mutltipliziere i2i2 mit 11.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+i2sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)+i2sin6(x)
Schritt 4.1.23
Schreibe i2i2 als -1−1 um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)-1sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)−1sin6(x)
Schritt 4.1.24
Schreibe -1sin6(x)−1sin6(x) als -sin6(x)−sin6(x) um.
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)-sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)−sin6(x)
cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)-sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)−sin6(x)
Schritt 4.2
Stelle die Faktoren in cos6(x)+6cos5(x)isin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)-sin6(x)cos6(x)+6cos5(x)isin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6cos(x)isin5(x)−sin6(x) um.
cos6(x)+6icos5(x)sin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6icos(x)sin5(x)-sin6(x)cos6(x)+6icos5(x)sin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6icos(x)sin5(x)−sin6(x)
cos6(x)+6icos5(x)sin(x)-15cos4(x)sin2(x)-20icos3(x)sin3(x)+15cos2(x)sin4(x)+6icos(x)sin5(x)-sin6(x)cos6(x)+6icos5(x)sin(x)−15cos4(x)sin2(x)−20icos3(x)sin3(x)+15cos2(x)sin4(x)+6icos(x)sin5(x)−sin6(x)
Schritt 5
Ziehe die Ausdrücke mit dem imaginären Teil heraus, welche gleich cos(6x)cos(6x) sind. Entferne die imaginäre Zahl ii.
cos(6x)=cos6(x)-15cos4(x)sin2(x)+15cos2(x)sin4(x)-sin6(x)cos(6x)=cos6(x)−15cos4(x)sin2(x)+15cos2(x)sin4(x)−sin6(x)