From my knowledge:
#=alpha
Sin:
x=#+2kpi and x=pi-#+2kpi
When u come out with the value of sine (alpha) you place it in the both cases and then you put it in the interval
0 <#+2kpi <2pi
Can someone help me find ALL solutions in the interval [0,2π) for the given equations. Please show work.
1) sin2x = sin2x
2) tan2x +tanx = 0
2 answers
#1 must be a joke. sin2x=sin2x for all x
#2
tan2x + tanx = 0
2tanx/(1-tan^2(x)) + tanx = 0
2tanx + tanx(1-tan^2(x)) = 0
tanx (2 + 1-tan^2x) = 0
tanx=0
tanx = ±√3
so, x=kπ or kπ ± π/3
Now just use the values of k so that the results come out in the desired domain.
#2
tan2x + tanx = 0
2tanx/(1-tan^2(x)) + tanx = 0
2tanx + tanx(1-tan^2(x)) = 0
tanx (2 + 1-tan^2x) = 0
tanx=0
tanx = ±√3
so, x=kπ or kπ ± π/3
Now just use the values of k so that the results come out in the desired domain.