Hallo,
Aufgabe 2)
f(x)=0
allg. gilt: sin(2x)=2 sin(x) cos(x)
2 (sin(x) - cos^3(x)) - sin(x) sin(2 x) =0 | + sin(x) sin(2 x)
2 (sin(x) - cos^3(x)) = sin(x) sin(2 x)
2 (sin(x) - cos^3(x)) = sin(x) *2 sin(x) cos(x) | :2
sin(x) - cos^3(x) = sin^2(x) cos(x) | -sin^2(x) cos(x)
sin(x) - cos^3(x) - sin^2(x) cos(x)= 0 ------>sin^2(x)= 1 -cos^2(x)
sin(x) - cos^3(x) - ( 1 -cos^2(x)) cos(x)= 0
sin(x) - cos^3(x) - ( cos(x) -cos^3(x)) = 0
sin(x) - cos^3(x) - cos(x) +cos^3(x) = 0
sin(x) - cos(x) = 0
sin(x) = cos(x) |:cos(x)
tan(x) =1
x= \( \frac{π}{4} \) +k*π ,k ∈G