Помогите срочно пожалуйста....3tg^2-8=4cos^2x

[latex]3tg^2x-8=4cos^2x\frac{3sin^2x}{cos^2x}-8=4cos^2x\frac{3sin^2x-8cos^2x}{cos^2x}=4cos^2x\3-3cos^2x-8cos^2x=4cos^4x\4cos^4x+11cos^2x-3=0\cos^2x=t,;cos^4x=t^2,;tin[0;;1]\4t^2+11t-3=0\D=121+4cdot4cdot3=169\t_{1,2}=frac{-11pm13}8\t_1=-3;-;He;nodx.\t_2=frac14\cos^2x=frac14\cos x=frac12Rightarrow x=pmfracpi3+2pi n\cos x=-frac12Rightarrow x=pmfrac{3pi}2+2pi n,;ninmathbb{Z}[/latex]