• 2≤x²+x<6 розвязати ............

Ответы 3

  •  2\leq x^2+x<6\quad \Rightarrow \; \; \left \{ {{x^2+x\geq 2} \atop {x^2+x<6}} ight.\; \left \{ {{x^2+x-2\geq 0} \atop {x^2+x-6<0}} ight. \; \left \{ {{(x-1)(x+2)\geq 0} \atop {(x-2)(x+3)<0}} ight. \\\\\left \{ {{x\in (-\infty ,-2\, ]\cup [\, 1,+\infty )} \atop {x\in (-3,2)}} ight.\; \; \Rightarrow \; \; \; x\in (-3,-2\, ]\cup [\, 1,2)\\\\\\+++++++[\, -2\, ]----[\, 1\, ]++++++\\+++(-3)-----------(2)+++

    • Автор:

      finley
    • 6 лет назад
    • 0
  • x^2+x≥2

    x^2+x-2≥0

    D=1+8=9

    x1=(-1+3)/2*1=2/2=1

    x2=(-1-3)/2*1=-4/2=-2

    (-oo;-2]U[1;+oo)

    x^2+x<6

    x^2+x-6<0

    D=1+24=25

    x1=(-1+5)/2*1=4/2=2

    x2=(-1-5)/2*1=-6/2=-3

    (-3;2)

    ///////////////////////////////////////////////////////////////////

    ______-3_____________-2__________1_________2_________

    \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

    (-3;-2]U[1;2)

  • x^2+x≥2

    x^2+x-2≥0

    D=1+8=9

    x1=(-1+3)/2*1=2/2=1

    x2=(-1-3)/2*1=-4/2=-2

    (-oo;-2]U[1;+oo)

    x^2+x<6

    x^2+x-6<0

    D=1+24=25

    x1=(-1+5)/2*1=4/2=2

    x2=(-1-5)/2*1=-6/2=-3

    (-3;2)

    ///////////////////////////////////////////////////////////////////

    ______-3_____________-2__________1_________2_________

    \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

    (-3;-2]U[1;2)

    • Автор:

      borja1ffx
    • 6 лет назад
    • 0
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