Maths

X squared-(k+3)x+4k=0
Please help me find the value of k for which there are equal roots but of opposite sign
Working out please thanks

asked by Jiskhaa
  1. Let r be the root:
    x²-(k+3)x+4k= 0 = (x-r)(x+r)=x²-r²
    equating coefficients,
    -(k+3)=0, k=-3
    4k=-r², r=sqrt(3*4)=2√3
    or the equation is
    x²-12=0
    Find k from the equation.

    posted by MathMate

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