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formel for sin(u+v)
Posted: 09/04-2020 15:22
by tron
Hvordan løser jeg denne?
2sin2x-cosx=0
x∈|0,360> (grader)
Re: formel for sin(u+v)
Posted: 09/04-2020 15:33
by Nebuchadnezzar
$\hspace{1cm}\sin(u+v) = \sin(u)\cos(v) + \sin(v)\cos(u)$
Re: formel for sin(u+v)
Posted: 09/04-2020 15:36
by ee01
2sin(2x)-cos(x)=0
2 * 2sin(x)*cos(x)-cos(x)=0
4sin(x)*cos(x)-cos(x)=0
cos(x)(4sin(x)-1)=0
=> cos(x)=0 V 4sin(x)=1
cos(x)=0 => x=(pi/2)+k*pi
4sin(x)=1 => x=arcsin(1/4)+2*pi*k
Så må du finne dei løysingane som ligg innanfor det gitte intervallet