bac nao giup em voi?

N

nguyenbahiep1

[TEX]\sqrt{3}x^2 - x + a +1=0 \\ \Delta = 1 - 4\sqrt{3}.(a+1) > 0 \\ a < \frac{1}{4.\sqrt{3}} - 1 \\ TH_1 : x_2 = 2x_1 \Rightarrow x_1+x_2 = 3x_1 = \frac{1}{\sqrt{3}} \Rightarrow x_1^2 = \frac{1}{27}\\ x_1.x_2 = 2x_1^2 = \frac{a+1}{\sqrt{3}} \Rightarrow x_1^2 = \frac{a+1}{2.\sqrt{3}} \\ \frac{a+1}{2.\sqrt{3}} = \frac{1}{27} \Rightarrow a = \frac{2.\sqrt{3}}{27} -1 (t/m) \\ TH_2 : x_1 = 2x_2[/TEX]

tự làm nốt

câu 2

[TEX]x_2 -x_1 = 3 \\ x_2 -x_1 = \frac{\sqrt{\Delta}}{\sqrt{3}} = 3 \\ \Delta = 1 - 4\sqrt{3}.(a+1) [/TEX]

tự làm nốt
 
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