Question

Anonim Help me. 3-4cos^2 t=0
2 cos^2 t-cos t = 0
4 cos^2 t-1=0
2 cos^2 t+cos t = 0

Answer 1

$1)3-4cos^2 t=0 \4cos^2t=3 \cos^2t= frac{3}{4} \cost= sqrt{frac{3}{4} }= frac{sqrt{3}}{2} \t_{1,2}=pm frac{pi}{6} +2pi n, n in Z \cost=- sqrt{frac{3}{4} }= -frac{sqrt{3}}{2} \t_{3,4}=pm frac{5pi}{6} +2pi n, n in Z \2)2 cos^2 t-cos t = 0 \cost(2cost-1)=0 \cost=0 \t_1= frac{pi}{2} +pi n, n in Z \2cost=1 \cost= frac{1}{2} \t_{2,3}= pm frac{pi}{3} +2pi n, n in Z$
$3)4 cos^2 t-1=0 \4cos^2t=1 \cos^2t= frac{1}{4} \cost=sqrt{frac{1}{4} }= frac{1}{2} \t_{1,2}= pm frac{pi}{3} +2pi n, n in Z \cost=-sqrt{frac{1}{4} }= -frac{1}{2} \t_{3,4}=pm frac{2pi}{3} +2pi n, n in Z \4)2 cos^2 t+cos t = 0 \cost(2cost+1)=0 \cost=0 \t_1= frac{pi}{2} +pi n, n in Z \2cost=-1 \cost= -frac{1}{2} \t_{2,3}=pm frac{2pi}{3} +2pi n, n in Z$

Answer 2

https://znanija.com/task/27122338 :)